improved PR todo list

Author: mtrezza

.github/PULL_REQUEST_TEMPLATE/pull_request_template.md

@@ -11,15 +11,15 @@
 ### Issue Description
 <!-- Add a brief description of the issue this PR solves. -->
 
-Related issue: #FILL_THIS_OUT
+Related issue: FILL_THIS_OUT
 
 ### Approach
 <!-- Add a description of the approach in this PR. -->
 
 ### TODOs before merging
 <!-- Add the TODOs that need to be completed before merging this PR. -->
 
-- [ ] ...
-- [ ] ...
 - [ ] Add test cases
-- [ ] Add changes to documentation
+- [ ] Add entry to changelog
+- [ ] Add changes to documentation (guides, repository pages, in-code descriptions)
+- [ ] ...