docs(chore): document git commit conventions

stephenplusplus · stephenplusplus · commit e8ae9ba01013 · 2014-09-18T08:32:13.000-04:00
To introduce contributors to our git conventions, our CONTRIBUTING.md
file now links to the AngularJS contributing document.
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
@@ -57,6 +57,28 @@ $ npm run cover
 
 The test coverage report will be available in `coverage/`.
 
+## Commit Guidelines
+
+We follow the AngularJS [commit conventions](ngcontributing). Please model your commit message after the following structure:
+
+```
+<type>(<scope>): <subject>
+<BLANK LINE>
+<body>
+<BLANK LINE>
+<footer>
+```
+
+- All lines must be limited to 72 characters
+- For `<scope>`, you may use:
+  - `app` for an application-wide change
+  - `datastore`
+  - `pubsub`
+  - `storage`
+  - etc.
+
+Be sure to read the AngularJS [contributing document][commitstandard]. For a thorough explanation, see the [AngularJS Git Commit Message Conventions doc][commitdoc].
+
 ## Contributor License Agreements
 
 Before we can accept your pull requests you'll need to sign a Contributor License Agreement (CLA):
@@ -70,3 +92,5 @@ You can sign these electronically (just scroll to the bottom). After that, we'll
 [gcloudcli]: https://developers.google.com/cloud/sdk/gcloud/
 [indvcla]: https://developers.google.com/open-source/cla/individual
 [corpcla]: https://developers.google.com/open-source/cla/corporate
+[ngcontributing]: https://github.com/angular/angular.js/blob/master/CONTRIBUTING.md#commit-message-format
+[commitdoc]: https://docs.google.com/document/d/1QrDFcIiPjSLDn3EL15IJygNPiHORgU1_OOAqWjiDU5Y/edit#
