[racket] Porter stemming algorithm

>> Many thanks for your interest. I have used the version just uploaded to
>> PLaneT
>> and it works. For a Racket ignoramus like me this is a buzz! Many thanks to
>> all.

Ok, I just added docs to it.  :)

Here: http://planet.racket-lang.org/package-source/dyoo/porter-stemmer.plt/1/2/planet-docs/manual/index.html

Documentation source:
https://github.com/dyoo/porter-stemmer/blob/master/manual.scrbl