setup pre-commit hooks for clang-format and prettier

.pre-commit-config.yaml

@@ -0,0 +1,12 @@
+fail_fast: false
+repos:
+  - repo: https://github.com/pocc/pre-commit-hooks
+    rev: master
+    hooks:
+      - id: clang-format
+        args:
+          - -i
+  - repo: https://github.com/prettier/prettier
+    rev: master
+    hooks:
+      - id: prettier

CONTRIBUTING.md

@@ -81,6 +81,11 @@ documentation to areas not currently covered are greatly appreciated.
 - To get started, from the `docs/` directory, run `npm ci` and then `npm start`.
 - Enhancements should be submitted as pull requests to the `main` branch of ZMK.
 
+### Formatting
+
+ZMK uses `prettier` to format documentation files. You can run prettier with `npm run prettier:format`.
+You can setup git to run prettier automatically when you commit by installing the pre-commit hooks: `pip3 install pre-commit`, `pre-commit install`.
+
 ## Code Contributions
 
 ### Development Setup
@@ -95,6 +100,8 @@ ZMK uses `clang-format` to ensure consist formatting for our source code. Before
 changes, make sure you've manually run `clang-format`, or have your IDE configured to auto-format
 on save.
 
+You can setup git to run `clang-format` automatically when you commit by installing the pre-commit hooks: `pip3 install pre-commit`, `pre-commit install`.
+
 ### Commit Messages
 
 The ZMK project is working towards, but not yet enforcing, the use of