README.rdoc in grb-0.4.0 vs README.rdoc in grb-0.4.1

@@ -19,9 +19,11 @@
     $ grb pull [branch] [--explain]
   * push branch `branch`, default current_branch
     $ grb push [branch] [--explain]
   * create new branch `branch`
     $ grb new [branch] [--explain]
+  * prune dead remote branches
+    $ grb prune
 
 Copyright (c) 2009-present MIT
 
 Author : Jinzhu Zhang
 Email  : [e-mail]