chore(github): Update issue template to use external main che repository

Change-Id: Ibfd0a7c31f06b9b87e839e3329bf2c103069c991
Signed-off-by: Florent Benoit <fbenoit@redhat.com>

.github/ISSUE_TEMPLATE/where-to-report-issues.md

@@ -0,0 +1,16 @@
+---
+name: "⚠️ Where to report issues ?"
+about: File issues on the main Eclipse Che repository at https://github.com/eclipse/che/issues
+title: Issues needs to be filed on the main Eclipse Che repository
+labels: ''
+assignees: ''
+
+---
+
+## Where to report issues?
+
+This repository is not the primary repository of Eclipse Che.
+
+🚨 Please don't submit new issues here. 🚨
+
+All issues for Eclipse Che are getting managed at: https://github.com/eclipse/che/issues