docs: update pull request template

.github/PULL_REQUEST_TEMPLATE.md

@@ -1,42 +1,3 @@
-<!--
-Thanks for your interest in the project. I appreciate bugs filed and PRs submitted!
+# This project is now in an unmaintained status. Please see the README for more information.
 
-Please make sure that you are familiar with and follow the Code of Conduct for
-this project (found in the CODE_OF_CONDUCT.md file).
-
-Also, please make sure you're familiar with and follow the instructions in the
-contributing guidelines (found in the CONTRIBUTING.md file).
-
-If you're new to contributing to open source projects, you might find this free
-video course helpful: http://kcd.im/pull-request
-
-Please fill out the information below to expedite the review and (hopefully)
-merge of your pull request!
--->
-
-<!-- What changes are being made? (What feature/bug is being fixed here?) -->
-
-**What**:
-
-<!-- Why are these changes necessary? -->
-
-**Why**:
-
-<!-- How were these changes implemented? -->
-
-**How**:
-
-<!-- Have you done all of these things?  -->
-
-**Checklist**:
-
-<!-- add "N/A" to the end of each line that's irrelevant to your changes -->
-
-<!-- to check an item, place an "x" in the box like so: "- [x] Documentation" -->
-
-* [ ] Documentation
-* [ ] Tests
-* [ ] Ready to be merged <!-- In your opinion, is this ready to be merged as soon as it's reviewed? -->
-* [ ] Added myself to contributors table <!-- this is optional, see the contributing guidelines for instructions -->
-
-<!-- feel free to add additional comments -->
+Only minimal changes will be merged.