Revise pull request template for clarity

Updated pull request template to clarify issue tracking.

Author: clairep94

.github/PULL_REQUEST_TEMPLATE.md

@@ -1,5 +1,5 @@
-### Fixes issue-number:
-<!-- Please add the issue this relates to -->
+### Context or Issue Number:
+<!-- Please add the issue this relates to if one is available. Otherwise please describe the current state of the codebase and what this PR attempts to fix. -->
 
 ### Demo:
 <!-- Please add a screenshot for UI related changes -->