Update CONTRIBUTING.md

Author: Kent C. Dodds

CONTRIBUTING.md

@@ -45,7 +45,7 @@ Please do the following:
 2. run `npm start` (if you're on a windows machine, see [this issue](https://github.com/formly-js/angular-formly/issues/305))
 3. write tests & code in ES6 goodness :-)
 4. run `git add src/`
-5. run `npm run commit` and follow the prompt (this ensures that your commit message follows our guidelines).
+5. run `npm run commit` and follow the prompt (this ensures that your commit message follows [our conventions](https://github.com/ajoslin/conventional-changelog/blob/master/conventions/angular.md)).
 6. notice that there's a pre-commit hook that runs to ensure tests pass and coverage doesn't drop to prevent the build from breaking :-)
 7. push your changes
 8. create a PR with a link to the original issue