docs: simplify pull request template

Author: woile

.github/pull_request_template.md

@@ -3,43 +3,27 @@ Thanks for sending a pull request!
 Please fill in the following content to let us know better about this change.
 -->
 
-## Types of changes
-
-<!-- Please put an `x` in the box that applies -->
-
-- [ ] **Bug fix**
-- [ ] **New feature**
-- [ ] **Refactoring**
-- [ ] **Breaking change** (any change that would cause existing functionality to not work as expected)
-- [ ] **Documentation update**
-- [ ] **Other (please describe)**
-
 ## Description
-
 <!-- Describe what the change is -->
 
+
 ## Checklist
 
 - [ ] Add test cases to all the changes you introduce
 - [ ] Run `./script/format` and `./script/test` locally to ensure this change passes linter check and test
 - [ ] Test the changes on the local machine manually
 - [ ] Update the documentation for the changes
 
-## Steps to Test This Pull Request
+## Expected behavior
+<!-- A clear and concise description of what you expected to happen -->
 
+
+## Steps to Test This Pull Request
 <!-- Steps to reproduce the behavior:
 1. ...
 2. ...
 3. ... -->
 
-## Expected behavior
-
-<!-- A clear and concise description of what you expected to happen -->
-
-## Related Issue
-
-<!-- If applicable, reference to the issue related to this pull request. -->
 
 ## Additional context
-
-<!-- Add any other context or screenshots about the pull request here. -->
+<!-- Add any other RELATED ISSUE, context or screenshots about the pull request here. -->