[PATCH] help: document branch template keyword

[Adrian Buehlmann]

# HG changeset patch
# User Adrian Buehlmann <adrian at cadifra.com>
# Date 1298804829 -3600
# Branch stable
# Node ID 6ec84cbcb94353fa8ed5d3c23caf989b54711121
# Parent  45b48be6b9105d3bd6f760d98bddcd4708df434b
help: document branch template keyword

The branch keyword was added in d79fdff55627

diff --git a/mercurial/help/templates.txt b/mercurial/help/templates.txt
--- a/mercurial/help/templates.txt
+++ b/mercurial/help/templates.txt
@@ -25,6 +25,9 @@ keywords are usually available for templ
 
 :author: String. The unmodified author of the changeset.
 
+:branch: String. The name of the branch on which the changeset was
+    committed.
+
 :branches: List of strings. The name of the branch on which the
     changeset was committed. Will be empty if the branch name was
     default.