chore: Update language of ISSUE_TEMPLATE. (#901)

Ask for link to repository first, add text explaining the importance of
linking a repository that demonstrates the bug.

ISSUE_TEMPLATE

@@ -1,10 +1,18 @@
 <!--Please use the template provided below when reporting bugs:-->
+## Link to bug demonstration repository.
+<!--
+A demo repository will show the combination of module versions being used,
+command-lines and configurations.  NYC is very complex, it is difficult or
+even impossible to triage most bugs without this information.
+
+If you cannot share a link to your repository (maybe it's private) then you must
+create a basic `nyc-bug-demo` repository and link to that please.
+-->
+
 ## Expected Behavior
 
 ## Observed Behavior
 
-## Bonus Points! Code (or Repository) that Reproduces Issue
-
 ## Forensic Information
 
 **Operating System:** the operating system you observed the issue on.