Try to nudge folks towards slack/mailing list for installation issues

.github/ISSUE_TEMPLATE.md

+GitHub issues are not meant for support questions. Please use the 
+[mailing list](https://groups.google.com/forum/#!forum/openedx-ops)
+or [Slack channels](https://open.edx.org/blog/open-edx-slack) to get help.
+
+Please open issues here to report bugs in the ansible scripts themselves.
+
+When reporting an issue, please include the following information.
+
+If `/edx/bin/show-repo-heads` is available on your system, it can provide much of this information:
+
+- Configuration ref:
+- edx-platform ref:
+- other refs:
+
+#Steps to replicate:
+- one
+- two
+- three