Merge pull request #45 from vshn/change/pr_template

Extend PR checklist

.github/PULL_REQUEST_TEMPLATE.md

@@ -1,19 +1,26 @@
-## Summary
 
-* Short summary of what's included in the PR
-* Give special note to breaking changes
+
 
 ## Checklist
 
-- [ ] Categorize the PR by setting a good title and adding one of the labels:
+- [ ] The PR has a meaningful title. It will be used to auto generate the
+      changelog.
+      The PR has a meaningful description that sums up the change. It will be
+      linked in the changelog.
+- [ ] PR contains a single logical change (to build a better changelog).
+- [ ] Update the documentation.
+- [ ] Categorize the PR by adding one of the labels:
       `bug`, `enhancement`, `documentation`, `change`, `breaking`, `dependency`
-      as they show up in the changelog
-- [ ] Update tests.
-- [ ] Link this PR to related issues.
+      as they show up in the changelog.
+- [ ] Link this PR to related issues or PRs.
 
 <!--
-Remove items that do not apply. For completed items, change [ ] to [x].
+Thank you for your pull request. Please provide a description above and
+review the checklist.
 
-NOTE: these things are not required to open a PR and can be done afterwards,
+Contributors guide: ./CONTRIBUTING.md
+
+Remove items that do not apply. For completed items, change [ ] to [x].
+These things are not required to open a PR and can be done afterwards,
 while the PR is open.
 -->