feat: adding pre-commit-hooks.yaml (#858)

Co-authored-by: Alexander Fenster <fenster@google.com>

.pre-commit-hooks.yaml

@@ -0,0 +1,9 @@
+- id: gts
+  name: gts
+  description: 'gts: TypeScript style guide, formatter, and linter.'
+  entry: gts lint
+  language: node
+  language_version: system
+  minimum_pre_commit_version: 2.9.2
+  require_serial: true
+  types_or: [javascript, jsx, ts, tsx]

README.md

@@ -77,6 +77,18 @@ Show your love for `gts` and include a badge!
 ## Supported Node.js Versions
 Our client libraries follow the [Node.js release schedule](https://nodejs.org/en/about/releases/). Libraries are compatible with all current _active_ and _maintenance_ versions of Node.js.
 
+## Can I use *gts* with the [pre-commit](https://pre-commit.com/) framework?
+
+Yes! You can put the following in your `.pre-commit-config.yaml` file:
+
+```yaml
+repos:
+  - repo: https://github.com/google/gts
+    rev: '' # Use the sha / tag you want to point at
+    hooks:
+      - id: gts
+```
+
 ## License
 [Apache-2.0](LICENSE)