How to write aboute pages for module

Is there a way to write about pages for own modules?

I would like to explain basic concepts of my modules in about pages. I already documented my cmdlets with ‘comment based help’

Unfortunately I couldn’t find any help how to create them. I looked at other modules like pester and noticed some *.help.txt files. Other modules provide xml files.

Is there any advice or best practice how to create them?

There is a program called PowerShell HelpWriter for XML-basert helpfiles: