Update PR template (#3866)

Signed-off-by: Cassandra Coyle <[email protected]>

Author: cicoyle

.github/pull_request_template.md

@@ -14,4 +14,7 @@ Please make sure you've completed the relevant tasks for this PR, out of the fol
 
 * [ ] Code compiles correctly
 * [ ] Created/updated tests
-* [ ] Extended the documentation / Created issue in the https://github.com/dapr/docs/ repo: dapr/docs#_[issue number]_
+* [ ] Extended the documentation
+    * [ ] Created the dapr/docs PR: <insert PR link here>
+
+**Note:** We expect contributors to open a corresponding documentation PR in the [dapr/docs](https://github.com/dapr/docs/) repository. As the implementer, you are the best person to document your work! Implementation PRs will not be merged until the documentation PR is opened and ready for review.