doc: PR templates.

Author: heinezen

.github/PULL_REQUEST_TEMPLATES/pull_request_template.md

@@ -0,0 +1,19 @@
+### Merge Checklist
+
+<!-- Complete all tasks below to make sure that we can merge your pull request. -->
+
+- [ ] I have read the [contribution guide](doc/contributing.md)
+- [ ] I have added my info to [copying.md](copying.md) (only first time contributors)
+- [ ] I have run `make checkall` and fixed all mentioned problems
+
+
+### Description
+
+<!-- Describe the changes this pull request makes to the code base. -->
+
+
+### Related Issue
+
+<!-- If this pull request is related to an issue, replace LINK with the link to the GitHub issue. -->
+
+Resolves LINK

.github/PULL_REQUEST_TEMPLATES/release_template.md

@@ -0,0 +1,7 @@
+### Checklist
+
+- [ ] Changelog
+    - [ ] Release date
+    - [ ] Version number in title
+    - [ ] Full commit log
+- [ ] Bump version in `openage_version`