add badges

README.md

@@ -1,2 +1,9 @@
 # terraform-registry
+
+[![BuildStatus](https://github.com/cappyzawa/terraform-registry/workflows/CI/badge.svg)](https://github.com/cappyzawa/terraform-registry/actions?query=workflow%3ACI)
+[![Go Report Card](https://goreportcard.com/badge/github.com/cappyzawa/terraform-registry)](https://goreportcard.com/report/github.com/cappyzawa/terraform-registry)
+[![PkgGoDev](https://pkg.go.dev/badge/github.com/cappyzawa/terraform-registry)](https://pkg.go.dev/github.com/cappyzawa/terraform-registry)
+[![codecov](https://codecov.io/gh/cappyzawa/terraform-registry/branch/master/graph/badge.svg)](https://codecov.io/gh/cappyzawa/terraform-registry)
+[![License: MIT](https://img.shields.io/badge/License-MIT-yellow.svg)](https://github.com/cappyzawa/terraform-registry/blob/main/LICENSE)
+
 WIP: The implementation of [Provider Registry Protocol \- Terraform by HashiCorp](https://www.terraform.io/docs/internals/provider-registry-protocol.html).