Make the root README more useful.

README

@@ -1,4 +1,11 @@
-For GNU/Linux instructions, please see our wiki page at:
-http://code.google.com/p/fofix/wiki/RunningUnderGNULinux
+This is Frets on Fire X, a highly customizable rhythm game supporting
+many modes of guitar, bass, drum, and vocal gameplay for up to four
+players. It is the continuation of a long succession of modifications
+to the original Frets on Fire by Unreal Voodoo.
 
-Also see documentation in the doc/ folder.
+Website: http://code.google.com/p/fofix/
+Repository (GitHub): http://github.com/stump/fofix
+  $ git clone git://github.com/stump/fofix.git
+
+For instructions on running from source, see RunningFromSource.mkd in
+the doc/ directory.