Update pull_request_template.md

Author: drmingdrmer

.github/pull_request_template.md

@@ -2,8 +2,17 @@
 Thank you for taking the time to open a pull request!
 Please review the checklist below and perform each of
 the applicable tasks. ❤️!
+
+A great pull-request has only one commit:
+Before publish a PR(already published PR should not be rebased), rebase your branch onto `main` and squash them into one commit with:
+`git update-ref refs/heads/my_branch $(echo "commit_message" | git commit-tree my_branch^{tree} -p main)`
+
+Replace `my_branch` and `commit_message` with actual values.
 -->
 
+
+
+
 **Checklist**
 
 - [ ] Updated guide with pertinent info (may not always apply). <!-- Mark complete if nothing to do. -->