Excavator: Ensure consistent PULL_REQUEST_TEMPLATE.md (#480)

Author: svc-excavator-bot

.github/ISSUE_TEMPLATE.md

@@ -0,0 +1,12 @@
+## What happened?
+
+<!--
+Describe what you've observed and why it's bad (please include whatever stacktraces/version numbers you can).
+Clear steps to reproduce the behaviour are always helpful too!
+-->
+
+## What did you want to happen?
+
+<!--
+Suggest better behaviour
+-->

.github/PULL_REQUEST_TEMPLATE.md

@@ -0,0 +1,11 @@
+## Before this PR
+<!-- What's wrong with the current state of the world and why change it now? -->
+
+## After this PR
+<!-- User-facing outcomes this PR delivers go below -->
+==COMMIT_MSG==
+==COMMIT_MSG==
+
+## Possible downsides?
+<!-- Please describe any way users could be negatively affected by this PR. -->
+