Log in, go to the documentation page you would like to work on and click on
"Edit" on the top right of the page. You will access the source of the page
and everything will be quite straightforward.
Of course, if you are unsure of what you have to do or afraid of breaking
something, you might ask away here or contact one of the current editors
listed at the bottom of the page. This is a collective edition work so any
change can be undone by going back to one of the previous versions.
Thanks for getting involved in updating the doc.
