docs: add badges and better installation instructions

README.md

@@ -1,6 +1,15 @@
 # gha-docs
 
+[![test](https://img.shields.io/github/workflow/status/matty-rose/gha-docs/Test%20GHA%20Docs)](https://github.com/matty-rose/gha-docs/actions/workflows/test.yaml)
+[![coverage](https://img.shields.io/codecov/c/github/matty-rose/gha-docs)](https://codecov.io/gh/matty-rose/gha-docs)
+[![Go Reference](https://pkg.go.dev/badge/github.com/matty-rose/gha-docs.svg)](https://pkg.go.dev/github.com/matty-rose/gha-docs)
+[![Go Report Card](https://goreportcard.com/badge/github.com/matty-rose/gha-docs)](https://goreportcard.com/report/github.com/matty-rose/gha-docs)
+[![license](https://img.shields.io/github/license/matty-rose/gha-docs)](https://github.com/matty-rose/gha-docs/blob/main/LICENSE)
+[![release](https://img.shields.io/github/v/release/matty-rose/gha-docs)](https://github.com/matty-rose/gha-docs/releases)
+
 ## Installation
+
+### Stable Release Binaries
 Substitute `darwin` for `linux` if installing on MacOS.
 
 ```bash
@@ -12,3 +21,15 @@ curl -LO https://github.com/matty-rose/gha-docs/releases/download/$GHA_DOCS_VERS
 tar -xzf gha-docs-$GHA_DOCS_VERSION-$GHA_DOCS_OS-$GHA_DOCS_ARCH.tar.gz
 chmod +x gha-docs && mv gha-docs /usr/local/bin
 ```
+
+### From Source
+
+Go `1.17+` is required.
+
+```bash
+go install github.com/matty-rose/[email protected]
+```
+
+## License
+
+MIT License - Copyright (c) 2021