docs: Add information about commit message guidelines

Author: lpatino10

.github/CONTRIBUTING.md

@@ -8,10 +8,7 @@ or [Stack Overflow](http://stackoverflow.com/questions/ask?tags=ibm-watson).
 # Code
 
 * Our style guide is based on [Google's](https://google.github.io/styleguide/jsguide.html), most of it is automaticaly enforced (and can be automatically applied with `npm run autofix`)
-* commits should start with the service name and end with the issue #
-  ```
-  [concept-insights] Added functionality to list the graphs #135
-  ```
+* Commits should follow the [Angular commit message guidelines](https://github.com/angular/angular/blob/master/CONTRIBUTING.md#-commit-message-guidelines). This is because our release tool uses this format for determining release versions and generating changelogs. To make this easier, we recommend using the [Commitizen CLI](https://github.com/commitizen/cz-cli) with the `cz-conventional-changelog` adapter.
 
 # Issues