Merge pull request #667 from chinapandaman/PPF-666

PPF-666: create PR template

.github/PULL_REQUEST_TEMPLATE.md

@@ -0,0 +1,17 @@
+### All Submissions:
+
+* [ ] Have you followed the guidelines in the [developer guide](https://chinapandaman.github.io/PyPDFForm/dev_intro/)?
+* [ ] Have you checked to ensure there aren't other open [Pull Requests](../../../pulls) for the same update/change?
+
+<!-- You can erase any parts of this template not applicable to your Pull Request. -->
+
+### New Feature Submissions:
+
+1. [ ] Does your submission pass tests?
+2. [ ] Have you lint your code locally prior to submission?
+
+### Changes to Core Features:
+
+* [ ] Have you added an explanation of what your changes do and why you'd like us to include them?
+* [ ] Have you written new tests for your core changes, as applicable?
+* [ ] Have you successfully ran tests with your changes locally?