patch applied (packages/Cabal): Add markdown version of user guide

[Ian Lynagh]

Sun Apr 11 09:10:12 PDT 2010  Duncan Coutts <duncan at haskell.org>
  * Add markdown version of user guide
  Plan is to switch over from docbook xml.

    A ./doc/Cabal.markdown

View patch online:
http://darcs.haskell.org/cgi-bin/darcsweb.cgi?r=packages/Cabal;a=darcs_commitdiff;h=20100411161012-adfee-c5f6599401ecdd8e70c79c1e169870d8e6a7c76a.gz