update README

README.md

@@ -1,11 +1,82 @@
 # tparallel
 [![tparallel](https://github.com/moricho/tparallel/workflows/tparallel/badge.svg?branch=master)](https://github.com/moricho/tparallel/actions)
+[![Go Report Card](https://goreportcard.com/badge/github.com/moricho/tparallel)](https://goreportcard.com/report/github.com/moricho/tparallel)
 [![MIT License](http://img.shields.io/badge/license-MIT-blue.svg?style=flat)](LICENSE)
 
-`tparallel`
+`tparallel` finds inappropriate usage of `t.Parallel()` method in your Go test codes.  
+This tool was inspired by this blog: [Go言語でのテストの並列化 〜t.Parallel()メソッドを理解する〜](https://engineering.mercari.com/blog/entry/how_to_use_t_parallel/)
 
 ## Install
 
+```sh
+$ go get github.com/moricho/tparallel/cmd/tparallel
+```
+
 ## Usage
 
+```sh
+$ go vet -vettool=`which tparallel` <pkgname>
+```
+
 ## Example
+
+```go
+package sample
+
+import (
+	"testing"
+)
+
+func Test_Table1(t *testing.T) {
+	teardown := setup("Test_Table1")
+	defer teardown()
+
+	tests := []struct {
+		name string
+	}{
+		{
+			name: "Table1_Sub1",
+		},
+		{
+			name: "Table1_Sub2",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+			call(tt.name)
+		})
+	}
+}
+
+func Test_Table2(t *testing.T) {
+	teardown := setup("Test_Table2")
+	t.Cleanup(teardown)
+	t.Parallel()
+
+	tests := []struct {
+		name string
+	}{
+		{
+			name: "Table2_Sub1",
+		},
+		{
+			name: "Table2_Sub2",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			call(tt.name)
+		})
+	}
+}
+```
+
+```console
+# github.com/moricho/tparallel/testdata/src/sample
+testdata/src/sample/table_test.go:7:6: Test_Table1 should use t.Cleanup
+testdata/src/sample/table_test.go:7:6: Test_Table1 should call t.Parallel on the top level
+testdata/src/sample/table_test.go:30:6: Test_Table2's sub tests should call t.Parallel
+```