The HelpWindow plugin provides some user documentation that looks as follows:

The contents of the documentation is the same as the one that can be found in the user documentation section of the OpenCOR website. This includes a menu that gets shown whenever you click on the information icon (top right):

Tool bar
Go to the home page
Go back
Go forward
Copy the selection to the clipboard
Reset the size of the help page contents
Zoom in the help page contents
Zoom out the help page contents
Print the help page contents