The Help module is responsible for handling all requests for documentation, and displaying it in an appropriate manner. Up to FreeCAD version 0.21, the Help module is available as an Addon, after that it is included in FreeCAD itself. There is no problem in leaving the Addon installed after version 0.21.
The Help module provides a preferences page under menu Edit → Preferences → General → Help, which allows to specify:
The Help module basically consists of a single Python module. Its main usage is using the show
function. It can retrieve an URL, a local file (Markdown or html), or find a page automatically from the settings set under Preferences → General → Help.
It doesn't matter what you provide, the system will recognize if the contents are HTML or Markdown and render it appropriately.
Basic usage:
import Help
Help.show("Draft Line")
Help.show("Draft_Line") # works with spaces or underscores
Help.show("https://wiki.freecadweb.org/Draft_Line")
Help.show("https://gitlab.com/freecad/FreeCAD-documentation/-/raw/main/wiki/Draft_Line.md")
Help.show("/home/myUser/.FreeCAD/Documentation/Draft_Line.md")
Help.show("http://myserver.com/myfolder/Draft_Line.html")