Add templates for bug and feature issues as well as PRs.

.github/PULL_REQUEST_TEMPLATE.md

@@ -0,0 +1,39 @@
+<!--
+Thank you very much for contributing code or documentation to rest-server!
+Please fill out the following questions to make it easier for us to review
+your changes.
+
+You do not need to check all the boxes below all at once, feel free to take
+your time and add more commits. If you're done and ready for review, please
+check the last box.
+-->
+
+
+What is the purpose of this change? What does it change?
+--------------------------------------------------------
+
+<!--
+Describe the changes here, as detailed as needed.
+-->
+
+
+Was the change discussed in an issue or in the forum before?
+------------------------------------------------------------
+
+<!--
+Link issues and relevant forum posts here.
+
+If this PR resolves an issue on GitHub, write "Closes #1234" such
+that the issue is closed automatically when this PR is merged.
+-->
+
+
+Checklist
+---------
+
+- [ ] I have added tests for all changes in this PR
+- [ ] I have added documentation for the changes (in the manual)
+- [ ] There's a new file in `changelog/unreleased/` that describes the changes for our users (template [here](https://github.com/restic/rest-server/blob/master/changelog/TEMPLATE))
+- [ ] I have run `gofmt` on the code in all commits
+- [ ] All commit messages are formatted in the same style as [the other commits in the repo](https://github.com/restic/rest-server/commits/master)
+- [ ] I'm done, this Pull Request is ready for review