docs: Added issue template

Author: edcarroll

.github/ISSUE_TEMPLATE.md

@@ -0,0 +1,17 @@
+Please read https://github.com/edcarroll/ng2-semantic-ui/blob/master/CONTRIBUTING.md and search
+existing issues (both open and closed) prior to opening any new issue and ensure you follow the instructions therein.
+
+### Bug description:
+
+### Link to minimally-working plunker that reproduces the issue:
+
+You can fork the [ng2-semantic-ui plunkr starter](http://plnkr.co/edit/SJMMMS8wQkwdX1HeMqiH?p=preview) and use it as a starting point.
+Please note that bug reports without a minimal reproduction scenario in plunker _cannot_ be acted on.
+
+### Version of Angular, ng2-semantic-ui, and Semantic UI:
+
+Angular:
+
+ng2-semantic-ui:
+
+Semantic UI: