add bug report template

.gitlab/issue_templates/Bug Report.md

@@ -0,0 +1,29 @@
+# Description
+
+Please describe the issue.
+
+# Steps to Reproduce
+
+1. ...
+2. ...
+3. ...
+
+# Expected Behavior
+
+Please describe the expected behavior.
+
+# Actual Behavior
+
+Please describe the actual behavior.
+
+# Additional Details
+
+These are optional, please add them if it makes sense.
+
+- ![Screenshot]()
+- [Logfile]()
+- ...
+
+# Possible Solutions
+
+If you have any suggestions on how to solve the issue, please add them here.