add issue template

.github/ISSUE_TEMPLATE.md

@@ -0,0 +1,9 @@
+Read the following before submitting your issue, thank you.
+
+- [] Use our mailing list to ask questions which don't imply an issue for feature request: https://groups.google.com/forum/#!forum/nwjs-general
+- [] State which version are you using
+- [] State which OS version are you running with
+- [] Provide a reproducible case if possible
+- [] Attach the crash dump file if it's a crash: http://docs.nwjs.io/en/latest/For%20Developers/Understanding%20Crash%20Dump/#find-minidump-file
+
+Issues meet the checklist above will be processed before those don't.