PDG documentation updated (April 2021)

[Mathias (Author)]

I was finally able to get the script running again that generate the PDF documentation from the webpage. 
So the PDF documentation is now updated again and I will now be able to keep it up to date.
(However some part of the documentation is obsolete. and need rewriting. I have not yet had the time for that)

http://multicommander.com/docs/