Update ISSUE_TEMPLATE.md

Added comment about the purpose of Issues...

Author: tristanmorgan

.github/ISSUE_TEMPLATE.md

@@ -1,5 +1,7 @@
 ### Subject of the issue
 
+**Issues and Pull requests should only be made for changes to the application code, not Tech Challenge Assessments.**
+
 Describe your issue here.
 
 ### Your environment
@@ -18,4 +20,4 @@ Tell us what should happen
 
 ### Actual behaviour
 
-Tell us what happens instead
+Tell us what happens instead