Add issue template

.gitlab/issue_templates/bug.md

@@ -0,0 +1,25 @@
+<!--
+Hello, thanks for reporting a bug. To help us with the debugging,
+please make sure to fill all the recommended information.
+Thanks!
+-->
+
+## Description
+
+General description of the bug.
+
+## Steps to reproduce
+
+1. Open app
+2. ...
+3. ...
+
+## System/Matrix Information
+
+**Distribution:** Ubuntu 20.04, openSUSE, ....
+**Qt Version:** 5.15.2
+**NeoChat version:** 1.2
+**Quotient version:** 0.6.6
+**Matrix server:** matrix.org, kde.org, ....
+
+/label Bug