docs: update pr template (#1099)

.github/pull_request_template.md

-Thank you for your contribution, we really appreciate it. The following instructions will help improve your pull request and make it easier to receive feedback. If there are any items you don't understand, don't worry. Just submit the pull request and ask the maintainers for help.
+<!-- Thank you for your contribution, we really appreciate it. The following instructions will help improve your pull request and make it easier to receive feedback. If there are any items you don't understand, don't worry. Just submit the pull request and ask the maintainers for help. -->
 
 ## Motivation
 
-Please explain the motivation behind this PR and the goal you aim to achieve with it.
+<!-- Please explain the motivation behind this PR and the goal you aim to achieve with it. -->
 
 ## Modification
 
-Briefly describe the changes made in this PR.
+<!-- Briefly describe the changes made in this PR. -->
 
 ## Checklist
 
--[] Before submitting a PR for review, make sure it has passed verification in your local development environment **at least**.
--[] Ensure pre-commit `pre-commit run --all-files` or other linting tools are used to fix potential lint issues.
--[] Confirm that modifications are covered by complete unit tests. If not, please add more unit tests for correctness.
--[] Modify documentation as needed, such as docstrings or example tutorials.
+- [ ] Before submitting a PR for review, make sure it has passed verification in your local development environment **at least**.
+- [ ] Ensure pre-commit `pre-commit run --all-files` or other linting tools are used to fix potential lint issues.
+- [ ] Confirm that modifications are covered by complete unit tests. If not, please add more unit tests for correctness.
+- [ ] Modify documentation as needed, such as docstrings or example tutorials.