Adjust GitHub templates

.github/PULL_REQUEST_TEMPLATE.md

@@ -1,18 +1,14 @@
-### Links to any relevant github issues:
+#### Purpose
+<br><br>
 
-- [Issue description](http://example.com/org/repo/issues/411). Any other useful information.
+#### Changes
+<br><br>
 
-### What's in the the PR
+#### Caveats
+<br><br>
 
-- [ ] A description of the changes proposed in the pull request.
-  - [ ] Any areas or issues reviewer should pay attention to? (comments in diff okay).
-- [ ] Update `/docs` to include, whenever possible, a new, suitable recommendation about how to use
-    the feature.
-- [ ] Extra Credit: [Confirm it runs and tests pass on the Rubies specified in the Travis
-  config](.travis.yml). A maintainer will otherwise confirm it runs on these.
-- [ ] *Bonus Points* Update [CHANGELOG.md](https://github.com/rails-api/active_model_serializers/blob/master/CHANGELOG.md)
-  with a brief description of any breaking changes, fixes, features, or
-  miscellaneous changes at the top of the proper version section.
+#### Related GitHub issues
+<br><br>
 
-For more general information, see [Submitting a pull request](
-https://github.com/rails-api/active_model_serializers/blob/master/CONTRIBUTING.md#submitting-a-pull-request-pr).
+#### Additonal helpful information
+<br><br>