ci: add PR template

This adds a simple template for PRs.

.github/PULL_REQUEST_TEMPLATE.md

@@ -0,0 +1,29 @@
+**Description**
+
+This PR fixes #
+
+**Notes for Reviewers**
+
+
+**[Signed commits](../CONTRIBUTING.md#signing-off-on-commits-developer-certificate-of-origin)**
+- [ ] Yes, I signed my commits.
+
+<!--
+Thank you for contributing to Masa! 
+
+Contributing Conventions
+-------------------------
+
+The draft above helps to give a quick overview of your PR.
+
+Remember to remove this comment and to at least:
+
+1. Include descriptive PR titles with [<component-name>] prepended. We use [conventional commits](https://www.conventionalcommits.org/en/v1.0.0/).
+2. Build and test your changes before submitting a PR. 
+3. Sign your commits
+4. **Tag maintainer:** for a quicker response, tag the relevant maintainer (see below).
+
+By following the community's contribution conventions upfront, the review process will 
+be accelerated and your PR merged more quickly.
+
+-->