git-svn: clarify explanation of --destination argument

The existing documentation for "-d" does not make it obvious whether
its argument is supposed to be a full svn path, a partial svn path,
the glob from the config file, or what.  Clarify the text and add an
example to get the reader started.

Reported-by: Nathan Gray <n8gray@n8gray.org>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Eric Wong <normalperson@yhbt.net>

Documentation/git-svn.txt

@@ -271,13 +271,15 @@ first have already been pushed into SVN.
 	Create a tag by using the tags_subdir instead of the branches_subdir
 	specified during git svn init.
 
--d;;
---destination;;
+-d<path>;;
+--destination=<path>;;
+
 	If more than one --branches (or --tags) option was given to the 'init'
 	or 'clone' command, you must provide the location of the branch (or
-	tag) you wish to create in the SVN repository.  The value of this
-	option must match one of the paths specified by a --branches (or
-	--tags) option.  You can see these paths with the commands
+	tag) you wish to create in the SVN repository.  <path> specifies which
+	path to use to create the branch or tag and should match the pattern
+	on the left-hand side of one of the configured branches or tags
+	refspecs.  You can see these refspecs with the commands
 +
 	git config --get-all svn-remote.<name>.branches
 	git config --get-all svn-remote.<name>.tags
@@ -1044,6 +1046,13 @@ Multiple fetch, branches, and tags keys are supported:
 	tags = tags/server/*:refs/remotes/project-a/tags/*
 ------------------------------------------------------------------------
 
+Creating a branch in such a configuration requires disambiguating which
+location to use using the -d or --destination flag:
+
+------------------------------------------------------------------------
+$ git svn branch -d branches/server release-2-3-0
+------------------------------------------------------------------------
+
 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