Add issue template

.github/ISSUE_TEMPLATE.md

@@ -0,0 +1,18 @@
+<!--
+Please include in the title whether this is a bug report or a feature request.
+
+Also, please search existing issues (both open and closed) to make sure what you're reporting or requesting hasn't already been reported or requested.
+
+If this is a question or general discussion topic, please start a conversation in our chat https://chat.pop-os.org in the ~cosmic-epoch channel.
+-->
+
+**Cosmic-app-library version:**
+<!-- (run `apt policy cosmic-app-library`, or the appropriate substitution for your package manager) -->
+
+**Issue/Bug description**
+
+**Steps to reproduce:**
+
+**Expected behavior:**
+
+**Other notes:**