docs: new cli install fragment

assets/docs/fragments/cli-installation.md

@@ -0,0 +1,62 @@
+### CLI Installation
+Follow the [AsyncAPI CLI installation](https://github.com/asyncapi/cli#installation) instructions below, based on your computer’s operating system.
+
+<details>
+<summary>MacOS</summary>
+
+`brew`
+</br>
+You can install in MacOS via brew: `brew install asyncapi`.
+
+`pkg`
+</br>
+Each release of CLI produces a MacOS dedicated pkg file that enables you to install this CLI as MacOS application.
+
+```
+# Download latest release. To download specific release, your link should look similar to https://github.com/asyncapi/cli/releases/download/v0.13.0/asyncapi.pkg. All releases are listed in https://github.com/asyncapi/cli/releases
+curl -OL https://github.com/asyncapi/cli/releases/latest/download/asyncapi.pkg
+# Install AsyncAPI CLI
+sudo installer -pkg asyncapi.pkg -target /
+```
+
+</details>
+
+<details>
+<summary>Linux</summary>
+
+You can install in Linux via `dpkg`, a debian package manager:
+
+1. `curl -OL https://github.com/asyncapi/cli/releases/latest/download/asyncapi.deb` 
+2. `sudo dpkg -i asyncapi.deb`
+
+</details>
+
+<details>
+<summary>Other OS</summary>
+
+[Read further AsyncAPI CLI installation instructions for different operating systems](https://github.com/asyncapi/cli#installation).
+</details>
+
+#### Using NPM and Node.js
+Alternitavely, you can install the [AsyncAPI CLI](https://github.com/asyncapi/cli#installation) with Node.js `>=v10` and [NPM](https://nodejs.org/en/download/package-manager/).
+
+<details>
+<summary>Install CLI globally</summary>
+
+Install AsyncAPI CLI _globally_ with the following command:
+
+```
+npm install -g @asyncapi/cli
+```
+</details>
+
+<details>
+<summary>Install specific CLI version</summary>
+
+To install a specific version of the AsyncAPI CLI, pass the `verion` during installation:
+
+```
+npm install -g @asyncapi/cli@{version}
+```
+
+</details>