Add PR template to hint at selecting the correct branch and labels

.github/pull_request_template.md

@@ -0,0 +1,6 @@
+<!--
+Pull requests regarding major or minor updates need to target the `develop` branch.
+Pull requests regarding patch updates need to target the `main` branch.
+Please make sure to select the appropriate branch while creating the pull request.
+For a reference on semantic versioning, see https://semver.org.
+-->