git main documentation: point at the user's manual.

Signed-off-by: Junio C Hamano <junkio@cox.net>

Documentation/git.txt

@@ -22,6 +22,9 @@ See this link:tutorial.html[tutorial] to get started, then see
 link:everyday.html[Everyday Git] for a useful minimum set of commands, and
 "man git-commandname" for documentation of each command.  CVS users may
 also want to read link:cvs-migration.html[CVS migration].
+link:user-manual.html[Git User's Manual] is still work in
+progress, but when finished hopefully it will guide a new user
+in a coherent way to git enlightenment ;-).
 
 The COMMAND is either a name of a Git command (see below) or an alias
 as defined in the configuration file (see gitlink:git-config[1]).