message: chore: add breaking change notice to PR template
diff: @@ -14,4 +14,10 @@ If your PR is the addition of a new operator, please make sure all these boxes a
  **Description:**
  +<!--
  +If this PR introduces a breaking change, it must contain a notice for it to be included in the CHANGELOG.
  +-->
  +
  +**BREAKING CHANGE:** <!-- add description or remove entirely if not breaking -->
  +
  **Related issue (if exists):**
  