docs: refine KCLVM readme (#182)

docs: update KCLVM readme.

.github/workflows/kcl.yml

@@ -0,0 +1,11 @@
+name: KCL
+on: ["push", "pull_request"]
+jobs:
+  build:
+    # Ref: https://github.com/actions/virtual-environments/blob/main/images/macos/macos-11-Readme.md
+    runs-on: ubuntu-latest
+    steps:
+      - name: Git checkout
+        uses: actions/checkout@v2
+        with:
+         submodules: 'true'

README-zh.md

@@ -0,0 +1,94 @@
+<h1 align="center">KCL: Constraint-based Record & Functional Language</h1>
+
+<p align="center">
+<a href="./README.md">English</a> | <a href="./README-zh.md">简体中文</a>
+</p>
+<p align="center">
+<a href="#介绍">介绍</a> | <a href="#特性">特性</a> | <a href="#场景">场景</a> | <a href="#安装">安装</a> | <a href="#快速开始">快速开始</a> | <a href="#文档">文档</a> | <a href="#贡献">贡献</a> | <a href="#路线规划">路线规划</a>
+</p>
+
+<p align="center">
+  <img src="https://github.com/KusionStack/KCLVM/workflows/KCL/badge.svg">
+  <img src="https://img.shields.io/badge/PRs-welcome-brightgreen.svg?style=flat-square">
+  <img src="https://coveralls.io/repos/github/KusionStack/KCLVM/badge.svg">
+  <img src="https://img.shields.io/github/release/KusionStack/KCLVM.svg">
+  <img src="https://img.shields.io/github/license/KusionStack/KCLVM.svg">
+</p>
+
+## 介绍
+
+Kusion 配置语言（KCL）是一个开源的基于约束的记录及函数语言。KCL 通过成熟的编程语言技术和实践来改进对大量繁杂配置的编写，致力于构建围绕配置的更好的模块化、扩展性和稳定性，更简单的逻辑编写，以及更快的自动化集成和良好的生态延展性。
+
+## 特性
+
++ **简单易用**：源于 Python、Golang 等高级语言，采纳函数式编程语言特性，低副作用
++ **设计良好**：独立的 Spec 驱动的语法、语义、运行时和系统库设计
++ **快速建模**：以 [Schema](https://kusionstack.io/docs/reference/lang/lang/tour#schema) 为中心的配置类型及模块化抽象
++ **功能完备**：基于 [Config](https://kusionstack.io/docs/reference/lang/lang/codelab/simple)、[Schema](https://kusionstack.io/docs/reference/lang/lang/tour/#schema)、[Lambda](https://kusionstack.io/docs/reference/lang/lang/tour/#%E5%87%BD%E6%95%B0)、[Rule](https://kusionstack.io/docs/reference/lang/lang/tour/#rule) 的配置及其模型、逻辑和策略编写
++ **可靠稳定**：依赖[静态类型系统](https://kusionstack.io/docs/reference/lang/lang/tour#%E7%B1%BB%E5%9E%8B%E7%B3%BB%E7%BB%9F)、约束和[自定义规则](https://kusionstack.io/docs/reference/lang/lang/tour#rule)的配置稳定性
++ **强可扩展**：通过独立配置块[自动合并机制](https://kusionstack.io/docs/reference/lang/lang/tour#%E9%85%8D%E7%BD%AE%E6%93%8D%E4%BD%9C)保证配置编写的高可扩展性
++ **易自动化**：[CRUD APIs](https://kusionstack.io/docs/reference/lang/lang/tour#kcl-%E5%8F%98%E9%87%8F%E4%BF%AE%E6%94%B9)，[多语言 SDK](https://kusionstack.io/docs/reference/lang/xlang-api/overview)，[语言插件](https://github.com/KusionStack/kcl-plugin) 构成的梯度自动化方案
++ **极致性能**：使用 Rust & C，[LLVM](https://llvm.org/) 实现，支持编译到本地代码和 [WASM](https://webassembly.org/) 的高性能编译时和运行时
++ **API 亲和**：原生支持 [OpenAPI](https://github.com/KusionStack/kcl-openapi)、 Kubernetes CRD， Kubernetes YAML 等 API 生态规范
++ **开发友好**：[语言工具](https://kusionstack.io/docs/reference/cli/kcl/) (Format，Lint，Test，Vet，Doc 等)、 [IDE 插件](https://github.com/KusionStack/vscode-kcl) 构建良好的研发体验
++ **安全可控**：面向领域，不原生提供线程、IO 等系统级功能，低噪音，低安全风险，易维护，易治理
+
+## 场景
+
+您可以将 KCL 用于
+
++ 生成静态配置数据如 JSON, YAML 等
++ 使用 schema 对配置数据进行建模并减少配置数据中的样板文件
++ 为配置数据定义带有规则约束的 schema 并对数据进行自动验证
++ 无副作用地组织、简化、统一和管理庞大的配置
++ 通过分块编写配置数据可扩展地管理庞大的配置
++ 与 [Kusion Stack](https://kusionstack.io) 一起，用作平台工程语言来交付现代应用程序
+
+## 安装
+
+从 Github releases 页面[下载](https://github.com/KusionStack/KCLVM/releases)，并且将 `{install-location}/kclvm/bin` 添加到您的环境变量中
+
+## 快速开始
+
+`./samples/fib.k` 是一个计算斐波那契数列的例子
+
+```kcl
+schema Fib:
+    n1 = n - 1
+    n2 = n1 - 1
+    n: int
+    value: int
+
+    if n <= 1:
+        value = 1
+    elif n == 2:
+        value = 1
+    else:
+        value = Fib {n = n1}.value + Fib {n = n2}.value
+
+fib8 = Fib {n = 8}.value
+```
+
+我们可以通过执行如下命令得到 YAML 输出
+
+```
+kcl ./samples/fib.k
+```
+
+YAML 输出
+
+```yaml
+fib8: 21
+```
+
+## 文档
+
+更多文档请访问[语言手册](https://kusionstack.io/docs/reference/lang/lang/tour)
+
+## 贡献
+
+参考[开发手册](./docs/dev_guide/1.about_this_guide.md).
+
+## 路线规划
+
+参考[KCLVM 路线规划](https://kusionstack.io/docs/governance/intro/roadmap#kclvm-%E8%B7%AF%E7%BA%BF%E8%A7%84%E5%88%92)

README.md

@@ -1,52 +1,61 @@
-# KCL
+<h1 align="center">KCL: Constraint-based Record & Functional Language</h1>
 
-![license](https://img.shields.io/badge/license-Apache--2.0-green.svg)
-[![Continuous Integration](https://github.com/KusionStack/KCLVM/actions/workflows/github-actions.yaml/badge.svg)](https://github.com/KusionStack/KCLVM/actions?query=branch%3Amain)
+<p align="center">
+<a href="./README.md">English</a> | <a href="./README-zh.md">简体中文</a>
+</p>
+<p align="center">
+<a href="#introduction">Introduction</a> | <a href="#features">Features</a> | <a href="#what-is-it-for">What is it for</a> | <a href="#installation">Installation</a> | <a href="#showcase">Showcase</a> | <a href="#documentation">Documentation</a> | <a href="#contributing">Contributing</a> | <a href="#roadmap">Roadmap</a>
+</p>
 
-[中文](./README_ZH.md)
+<p align="center">
+  <img src="https://github.com/KusionStack/KCLVM/workflows/KCL/badge.svg">
+  <img src="https://img.shields.io/badge/PRs-welcome-brightgreen.svg?style=flat-square">
+  <img src="https://coveralls.io/repos/github/KusionStack/KCLVM/badge.svg">
+  <img src="https://img.shields.io/github/release/KusionStack/KCLVM.svg">
+  <img src="https://img.shields.io/github/license/KusionStack/KCLVM.svg">
+</p>
 
-Kusion Configuration Language (KCL) is an open source configuration language mainly used in [Kusion Stack](https://kusionstack.io). KCL is a statically typed language for configuration and policy scenarios, based on concepts such as declarative and Object-Oriented Programming (OOP) paradigms.
+## Introduction
 
-## Core Features
+Kusion Configuration Language (KCL) is an open source constraint-based record and functional language. KCL improves the writing of a large number of complex configurations through mature programming language technology and practice, and is committed to building better modularity, scalability and stability around configuration, simpler logic writing, fast automation and good ecological extensionality.
 
-+ **Simple**
-  + Originated from Python and Golang, incorporating functional language features.
-  + Absorbs integrated language elements such as statements, expressions, conditions, loops, etc.
-  + Type and data separation, schema declaration configuration definition.
-+ **Stable**
-  + Strong immutable constraint.
-  + Compile-time type deduction, type checking.
-  + Rule policy definition: attribute-centric constraint expressions, query results based on constraints.
-  + Testable: assert, print, and test tools.
-+ **Scalable**
-  + Configuration unification: compile-time configuration dependency graph substitution.
-  + Configuration attribute operators: meet the needs of configuration override, merge, add and delete, etc.
-  + Configuration reuse: rich built-in data structures and syntax semantics, easily to expand one configuration of different scenarios.
-+ **Engineering**
-  + Schema single inheritance and declarative model reuse and assembly.
-  + Tool & API granular configuration automation.
-  + Rich built-in functions and system libraries.
-  + Top-level dynamic data input.
-  + Code organization: modules and packages.
-  + [Plug-in system](https://github.com/KusionStack/kcl-plugin): reuse common programming language ecology.
-  + [OpenAPI model support](https://github.com/KusionStack/kcl-openapi): Swagger and KCL schema bidirectional conversion, Kubernetes CRD conversion to KCL schema.
-+ **High Performance**
-  + Works with the LLVM optimizer, supports compilation to native code and formats like WASM and executes efficiently.
+## Features
 
-## Installing & Documentation
++ **Easy-to-use**: Originated from high-level languages ​​such as Python and Golang, incorporating functional language features with low side effects.
++ **Well-designed**: Independent Spec-driven syntax, semantics, runtime and system modules design.
++ **Quick modeling**: [Schema](https://kusionstack.io/docs/reference/lang/lang/tour#schema)-centric configuration types and modular abstraction.
++ **Rich capabilities**: Configuration with type, logic and policy based on [Config](https://kusionstack.io/docs/reference/lang/lang/codelab/simple), [Schema](https://kusionstack.io/docs/reference/lang/lang/tour/#schema), [Lambda](https://kusionstack.io/docs/reference/lang/lang/tour/#%E5%87%BD%E6%95%B0), [Rule](https://kusionstack.io/docs/reference/lang/lang/tour/#rule).
++ **Stability**: Configuration stability built on [static type system](https://kusionstack.io/docs/reference/lang/lang/tour/#%E7%B1%BB%E5%9E%8B%E7%B3%BB%E7%BB%9F), constraints, and [rules](https://kusionstack.io/docs/reference/lang/lang/tour#rule).
++ **Scalability**: High scalability through [automatic merge mechanism](https://kusionstack.io/docs/reference/lang/lang/tour#%E9%85%8D%E7%BD%AE%E6%93%8D%E4%BD%9C) of isolated config blocks.
++ **Fast automation**: Gradient automation scheme of [CRUD APIs](https://kusionstack.io/docs/reference/lang/lang/tour#kcl-%E5%8F%98%E9%87%8F%E4%BF%AE%E6%94%B9), [multilingual SDKs](https://kusionstack.io/docs/reference/lang/xlang-api/overview), [language plugin](https://github.com/KusionStack/kcl-plugin)
++ **High performance**: High compile time and runtime performance using Rust & C and [LLVM](https://llvm.org/), and support compilation to native code and [WASM](https://webassembly.org/).
++ **API affinity**: Native support API ecological specifications such as [OpenAPI](https://github.com/KusionStack/kcl-openapi), Kubernetes CRD, Kubernetes YAML spec.
++ **Development friendly**: Friendly development experiences with rich [language tools](https://kusionstack.io/docs/reference/cli/kcl/) (Format, Lint, Test, Vet, Doc, etc.) and [IDE plugins](https://github.com/KusionStack/vscode-kcl).
++ **Safety & maintainable**: Domain-oriented, no system-level functions such as native threads and IO, low noise and security risk, easy maintenance and governance.
 
-### How to install
+## What is it for?
 
-[Download](https://github.com/KusionStack/KCLVM/releases) the latest release from GitHub and add `{install-location}/kclvm/bin` to environment PATH.
+You can use KCL to
 
-### Quick Showcase
++ Generate low-level static configuration data like JSON, YAML, etc.
++ Reduce boilerplate in configuration data with the schema modeling.
++ Define schemas with rule constraints for configuration data and validate them automatically.
++ Organize, simplify, unify and manage large configurations without side effects.
++ Manage large configurations scalably with isolated configuration blocks.
++ Used as a platform engineering lang to deliver modern app with [Kusion Stack](https://kusionstack.io).
+
+## Installation
+
+[Download](https://github.com/KusionStack/KCLVM/releases) the latest release from GitHub and add `{install-location}/kclvm/bin` to the environment `PATH`.
+
+## Showcase
 
 `./samples/fib.k` is an example of calculating the Fibonacci sequence.
 
 ```kcl
 schema Fib:
-    n1: int = n - 1
-    n2: int = n1 - 1
+    n1 = n - 1
+    n2 = n1 - 1
     n: int
     value: int
 
@@ -55,9 +64,9 @@ schema Fib:
     elif n == 2:
         value = 1
     else:
-        value = Fib {n: n1}.value + Fib {n: n2}.value
+        value = Fib {n = n1}.value + Fib {n = n2}.value
 
-fib8 = Fib {n: 8}.value
+fib8 = Fib {n = 8}.value
 ```
 
 We can execute the following command to get a YAML output.
@@ -72,20 +81,14 @@ YAML output
 fib8: 21
 ```
 
-### Documentation
+## Documentation
 
-Detailed documentation is available at https://kusionstack.io
+Detailed documentation is available at [KCL tour](https://kusionstack.io/docs/reference/lang/lang/tour)
 
-## Developing & Contributing
-
-### Developing
+## Contributing
 
 See [Developing Guide](./docs/dev_guide/1.about_this_guide.md).
 
-### Roadmap
-
-See [KCLVM Roadmap](https://kusionstack.io/docs/governance/intro/roadmap#kclvm-%E8%B7%AF%E7%BA%BF%E8%A7%84%E5%88%92)
-
-## License
+## Roadmap
 
-Apache License Version 2.0
+See [KCLVM Roadmap](https://kusionstack.io/docs/governance/intro/roadmap#kclvm-%E8%B7%AF%E7%BA%BF%E8%A7%84%E5%88%92).

samples/fib.k

@@ -1,6 +1,6 @@
 schema Fib:
-    n1: int = n - 1
-    n2: int = n1 - 1
+    n1 = n - 1
+    n2 = n1 - 1
     n: int
     value: int
 
@@ -9,6 +9,6 @@ schema Fib:
     elif n == 2:
         value = 1
     else:
-        value = Fib {n: n1}.value + Fib {n: n2}.value
+        value = Fib {n = n1}.value + Fib {n = n2}.value
 
-fib8 = Fib {n: 8}.value
+fib8 = Fib {n = 8}.value