git-svn: multiple fetch/branches/tags keys are supported

"git svn" can be configured to use multiple fetch, branches, and tags
refspecs by passing multiple --branches or --tags options at init time
or editing the configuration file later, which can be handy when
working with messy Subversion repositories.  Add a note to the
configuration section documenting how this works.
Signed-off-by: NJonathan Nieder <jrnieder@gmail.com>
Signed-off-by: NEric Wong <normalperson@yhbt.net>

Documentation/git-svn.txt

@@ -1032,6 +1032,18 @@ comma-separated list of names within braces. For example:
 	tags = tags/{1.0,2.0}/src:refs/remotes/tags/*
 ------------------------------------------------------------------------
 
+Multiple fetch, branches, and tags keys are supported:
+
+------------------------------------------------------------------------
+[svn-remote "messy-repo"]
+	url = http://server.org/svn
+	fetch = trunk/project-a:refs/remotes/project-a/trunk
+	fetch = branches/demos/june-project-a-demo:refs/remotes/project-a/demos/june-demo
+	branches = branches/server/*:refs/remotes/project-a/branches/*
+	branches = branches/demos/2011/*:refs/remotes/project-a/2011-demos/*
+	tags = tags/server/*:refs/remotes/project-a/tags/*
+------------------------------------------------------------------------
+
 Note that git-svn keeps track of the highest revision in which a branch
 or tag has appeared. If the subset of branches or tags is changed after
 fetching, then .git/svn/.metadata must be manually edited to remove (or