Update issue_template.md

Author: Bios-Marcel

.github/issue_template.md

@@ -1,18 +1,20 @@
 <!--
-Please fill out the form below, in order to allow developers to easily solve your problem
+Please fill out the form below, in order to allow developers to easily solve your problem.
+
+Delete everything in this editor if your issue is not a bug report.
 -->
 
-#Description
-##Expected behaviour
+# Description
+##  Expected behaviour
 TODO
 
-##Actual behaviour
+## Actual behaviour
 TODO
 
 ## Error message
 TODO (If known)
 
-#Additional Information (Optional)
+# Additional Information (Optional)
 ## Stacktrace
 TODO
 ## Operating System