editing the wiki

Dear Ratpoison developers,
I would like to help Ratpoison, by editing particular pages and
I saw this page: http://ratpoison.wxcvbn.org/cgi-bin/wiki.pl/wesnoth
I often play this game (and use Ratpoison), and would like to add some 
information about playing it.
There are various other pages I would like to expand.
However I see it needs a `username'. Do I need to make some sort of 
account,
and if so, how; or do I just add it under some user-name?
I would like to help code but currently I am learning still. I use 
Debian GNU/Linux 8.

Thanks,
D Guthrie