Update issue template to point to Jira (broadinstitute#4995)

.github/issue_template.md

@@ -1,7 +1,15 @@
+###
+### IMPORTANT: Please file new issues over in our Jira issue tracker!
+###
+### https://broadworkbench.atlassian.net/projects/BA/issues
+###
+### You may need to create an account before you can view/create issues.
+###
+
 <!--
 Hi!  Thanks for taking the time to report feedback.
 
-Before posting an issue here, please check whether your question is already answered in our:
+Before posting an issue over in Jira tracker, please check whether your question is already answered in our:
   forum  https://gatkforums.broadinstitute.org/wdl/categories/ask-the-wdl-team
   documentation http://cromwell.readthedocs.io/en/develop/
 
@@ -11,7 +19,9 @@ WDL https://gatkforums.broadinstitute.org/wdl/categories/ask-the-wdl-team
 CWL https://www.biostars.org/
 -->
 
-<!-- Are you seeing something that looks like a bug?  Then great!  You're in the right place.  -->
+<!-- Are you seeing something that looks like a bug?  Then great!  You're almost in the right place.  -->
+
+<!-- You'll want to go to https://broadworkbench.atlassian.net/projects/BA/issues and then tell us: -->
 
 <!-- Which backend are you running?  -->