Create PR template for release notes (#100)

* Create PR template for release notes

* Wording tweak in release notes section

Co-authored-by: Nik Richers <nik@validmind.ai>

* Wording tweak for labels

Co-authored-by: Nik Richers <nik@validmind.ai>

* Fix capitalization

Co-authored-by: Nik Richers <nik@validmind.ai>

* Fix capitalization

Co-authored-by: Nik Richers <nik@validmind.ai>

* Update pull_request_template.md

* Minor line spacing tweaks

---------

Co-authored-by: Nik Richers <nik@validmind.ai>

Author: sydneysugar

.github/workflows/pull_request_template.md

@@ -0,0 +1,9 @@
+## Internal notes for reviewers
+
+<!--start release notes section -->
+## External Release Notes
+
+Please provide a description that allows an external user to understand the changes made, even without access to the original pull request.
+
+If this is an internal-only change, add the `internal` label to omit the changes from the external release notes.
+<!-- end release notes section -->