Improve readme (#5)

.gitignore

@@ -1,2 +1,6 @@
 bin/
 vendor/
+
+# test coverage
+coverage.out
+coverage.html

README.md

@@ -1,2 +1,40 @@
 # gomockcontrollerfinish
+
+![CI](https://github.com/hendrywiranto/gomockcontrollerfinish/workflows/CI/badge.svg)
+[![Go Report Card](https://goreportcard.com/badge/github.com/hendrywiranto/gomockcontrollerfinish)](https://goreportcard.com/report/github.com/hendrywiranto/gomockcontrollerfinish)
+[![Coverage Status](https://coveralls.io/repos/github/hendrywiranto/gomockcontrollerfinish/badge.svg?branch=main)](https://coveralls.io/github/hendrywiranto/gomockcontrollerfinish?branch=main)
+[![MIT License](http://img.shields.io/badge/license-MIT-blue.svg?style=flat)](LICENSE)
+
 A linter that checks whether an unnecessary call to .Finish() on gomock.Controller exists
+
+## Installation & usage
+
+```
+$ go install github.com/hendrywiranto/gomockcontrollerfinish@latest
+$ gomockcontrollerfinish ./...
+```
+
+or use `go vet`
+```
+$ go build -o gomockcontrollerfinish main.go
+$ go vet -vettool=./gomockcontrollerfinish ./...
+```
+
+## Motivation
+As highlighted in https://pkg.go.dev/github.com/golang/mock/gomock#NewController
+
+>New in go1.14+, if you are passing a *testing.T into this function you no longer need to call ctrl.Finish() in your test methods.  
+
+## Examples
+```
+// Bad
+func TestFoo(t *testing.T) {
+	mock := gomock.NewController(t)
+	defer mock.Finish() // no need to call this since go1.14
+}
+
+// Good
+func TestFoo(t *testing.T) {
+	mock := gomock.NewController(t)	
+}
+```