STYLE: Updated bug report template

.gitlab/issue_templates/bug.md

-<!---
-Please read this!
+<!--
+  *** Please read this first! ***
 
-Before opening a new issue, make sure to search for keywords in the issues
-filtered by the "bug" label and check to see if it has already been reported
---->
+  Before opening a new issue, make sure to search for keywords in the issues
+  filtered by the "bug" label and check to see if it has already been reported
+-->
+
+<!--
+  All text between these markers are comments and will not be present in the
+  report
+-->
 
 ### Summary
 
-(Summarize the bug encountered concisely)
+<!-- Summarize the bug encountered concisely -->
 
 
 ### Steps to reproduce
 
-(How one can reproduce the issue - this is very important)
+<!-- How one can reproduce the issue - this is very important -->
 
 
 ### Example case
 
-(If possible, please create a SMALL example case and attach it to your bug report)
+<!--
+  If possible, please create a SMALL example and attach it to your report
 
-(If you are using an older version of OpenFOAM this will also determine whether the bug has been fixed in a more recent version)
+  If you are using an older version of OpenFOAM this will also determine
+  whether the bug has been fixed in a more recent version
+-->
 
 
 ### What is the current *bug* behaviour?
 
-(What actually happens)
+<!-- What actually happens -->
 
 
 ### What is the expected *correct* behavior?
 
-(What you should see instead)
+<!-- What you should see instead -->
 
 
 ### Relevant logs and/or images
 
-(Paste any relevant logs - please use code blocks (```) to format console output,
-logs, and code as it's very hard to read otherwise.)
+<!--
+  Paste any relevant logs - please use code blocks (```) to format console
+  output, logs, and code as it's very hard to read otherwise.
+-->
 
 
 ### Environment information
 
-(OpenFOAM version : XXX)
-(Operating system : XXX)
-(Hardware info    : XXX)
-
+<!--
+  Providing details of your set-up can help us identify any issues, e.g.
+  OpenFOAM version : v1806|v1812|v1906 etc
+  Operating system : ubuntu|openSUSE|centos etc
+  Hardware info    : any info that may help?
+  Compiler         : gcc|intel|clang etc
+ -->
+OpenFOAM version :
+Operating system :
+Compiler         :
 
 ### Possible fixes
 
-(If you can, link to the line of code that might be responsible for the problem)
+<!--
+  If you can, link to the line of code that might be responsible for the
+  problem
+-->
 
 /label ~bug