[fpc-pascal] DOS compiler wiki page: please review

[Reinier Olislagers]

I decided to start a page for the DOS compiler - as more details become
available we can hopefully collect them there.

As usual: additions/corrections welcome, especially by Nikolay ;) - I've
added some statements with question marks that I'm not sure about.
http://wiki.lazarus.freepascal.org/DOS

Thanks,
Reinier (who's very keen to get another fairly simple cross compiler
working using fpcup :) )