doc: add pr template (#11819)

.github/pull_request_template.md

+<!-- Please fill in the following information to help us review your PR more efficiently. -->
+
+## Brief Information
+
+This pull request is in the type of:
+
+- [ ] bug fixing
+- [ ] new feature
+- [ ] others
+
+
+
+### What does this PR do?
+
+<!-- USE ONCE SENTENCE TO DESCRIBE WHAT THIS PR DOES. -->
+
+
+
+### Fixed issues
+
+<!--
+- #xxxx: ...
+-->
+
+
+## Details
+
+### Before: What was the problem?
+
+<!-- DESCRIBE THE BUG OR REQUIREMENT HERE. -->
+
+<!-- ADD SCREENSHOT HERE IF APPLICABLE. -->
+
+
+
+### After: How is it fixed in this PR?
+
+<!-- THE RESULT AFTER FIXING AND A SIMPLE EXPLANATION ABOUT HOW IT IS FIXED. -->
+
+<!-- ADD SCREENSHOT HERE IF APPLICABLE. -->
+
+
+
+## Usage
+
+### Are there any API changes?
+
+- [ ] The API has been changed.
+
+<!-- LIST THE API CHANGES HERE -->
+
+
+
+### Related test cases or examples to use the new APIs
+
+NA.
+
+
+
+## Others
+
+### Merging options
+
+- [ ] Please squash the commits into a single one when merge.
+
+### Other information