add pull request template

.github/workflows/pull_request_template.md

@@ -0,0 +1,18 @@
+**Checklist** <!-- Mandatory -->
+
+Please verify the following checklist in order:
+- [ ] If releasing module changes, the Pull Request title is prepended with "[\<Azure Stack Hub Release Version\>]". E.g., a title may be "[2301] Compute RP changes". Otherwise, this is not necessary.
+- [ ] Updated origin `dev` branch locally. (`git fetch origin dev`)
+- [ ] The Pull Request has a single commit. The following is a standard way to achieve a single commit:
+    - `git checkout feature`
+    - `git rebase origin/dev -i`
+    - In the VIM editor press `ESC` and `i` to enter edit mode.
+    - Select commits to fixup or squash commits (instructions are in the editor).
+    - Press `ESC`, type `:wq`, and press `Enter` to save and quit.
+- [ ] Resolved any rebase conflicts (basically merge conflicts).
+- [ ] Commits are rebased on top of latest remote `dev` branch.
+- [ ] The changes are tested. Make sure to test after the rebase step.
+- [ ] Updated remote feature branch. (Force push if you've rebased onto new changes from dev: `git push origin feature -f`)
+
+**Description** <!-- Mandatory -->
+<!-- Give a detailed description of the changes. For small changes, you can just copy the single commit message. If releasing a new module version, this can be the same as the changelog update. If for some reason the pull request requires multiple commits, explain why that is required as well. -->