Add PR template

.github/PULL_REQUEST_TEMPLATE.md

@@ -0,0 +1,15 @@
+## Description (e.g. "Related to ...", etc.)
+
+_Please replace this description with a concise description of this Pull Request._
+
+## Code review checklist (for code reviewer to complete)
+
+- [ ] Pull request represents a single change (i.e. not fixing disparate/unrelated things in a single PR)
+- [ ] Title summarizes what is changing
+- [ ] Commit messages are meaningful (see [this][commit messages] for details)
+- [ ] Tests have been included and/or updated, as appropriate
+- [ ] Docstrings have been included and/or updated, as appropriate
+- [ ] Changelog has been updated, as needed (see [CHANGELOG.md][changelog])
+
+[changelog]: https://github.com/openlawlibrary/taf/blob/master/CHANGELOG.md
+[commit messages]: https://chris.beams.io/posts/git-commit/