Fix broken GitHub Actions badge (#399)

Author: wata727

README.md

@@ -1,5 +1,5 @@
 # TFLint Ruleset for terraform-provider-google
-[![Build Status](https://github.com/terraform-linters/tflint-ruleset-google/workflows/build/badge.svg?branch=master)](https://github.com/terraform-linters/tflint-ruleset-google/actions)
+[![Build Status](https://github.com/terraform-linters/tflint-ruleset-google/actions/workflows/build.yml/badge.svg?branch=master)](https://github.com/terraform-linters/tflint-ruleset-google/actions)
 [![GitHub release](https://img.shields.io/github/release/terraform-linters/tflint-ruleset-google.svg)](https://github.com/terraform-linters/tflint-ruleset-google/releases/latest)
 [![License: MPL 2.0](https://img.shields.io/badge/License-MPL%202.0-blue.svg)](LICENSE)