Add Awesome Go badge to README

Added badge for 'Mentioned in Awesome Go' to README.

Author: jferrl

README.md

@@ -4,6 +4,7 @@
 [![Test Status](https://github.com/jferrl/go-githubauth/workflows/tests/badge.svg)](https://github.com/jferrl/go-githubauth/actions?query=workflow%3Atests)
 [![codecov](https://codecov.io/gh/jferrl/go-githubauth/branch/main/graph/badge.svg?token=68I4BZF235)](https://codecov.io/gh/jferrl/go-githubauth)
 [![Go Report Card](https://goreportcard.com/badge/github.com/jferrl/go-githubauth)](https://goreportcard.com/report/github.com/jferrl/go-githubauth)
+[![Mentioned in Awesome Go](https://awesome.re/mentioned-badge.svg)](https://github.com/avelino/awesome-go)
 
 `go-githubauth` is a Go package that provides utilities for GitHub authentication, including generating and using GitHub App tokens, installation tokens, and personal access tokens.