Wiki is usually for general informations, in my opinion, like wikipedia, or programming languages, or script language like wiki.tcl.tk.
It is not a good idea for FEAP to make a wiki, as it is more specific, based on Fortran, etc. Instead, there is a need to improve the documentation.
I thick there are some valuable sources in the forum that could be documented.
At the beginning, I found a discussion about meshing of a sphere, which is very impressive example, and should be documented!
If you have tried to find some reference examples, probably you will find some good ones here,
http://code-aster.org, which is a French FEM program.
I never used it, and I can't compared it with FEAP. But even if the documentation is still questionable, but still there are something that could be useful.
It is finally a question of time, effort, and maybe also research interest.
I wish the best.