fix(PLT-3430): Combine templates (#238)

Author: georgegillams

.github/PULL_REQUEST_TEMPLATE.md

@@ -21,3 +21,12 @@ Jira ticket: https://typeform.atlassian.net/browse/<TICKET_ID>
 ## Docs
 
 - [ ] **Yes!** :hand: I have updated the documentation.
+
+## For contributions to the `Typeform/.github` repo
+
+Note: Please do not use this repository for new internal shared workflows and actions. Use https://github.com/Typeform/.github-private instead!
+
+Please check that your contribution applies to one of these cases below. If this is not the case, please contribute to https://github.com/Typeform/.github-private instead.
+
+- [ ] This PR only changes an existing workflow.
+- [ ] This PR adds a new workflow that is needed in a public Typeform repository.