Added notes to README to explain more submodule use.

README

@@ -17,6 +17,17 @@ git submodule init
 git submodule update
 
 
+
 # Add more vim plugins from this dotFiles directory, like so:
 #
 # git submodule add git://github.com/tpope/vim-pathogen.git vim/bundle/pathogen
+
+
+
+# Apart from updating plugins individually, you can update all submodules in one shot
+#
+# git submodule foreach git pull origin master
+
+
+
+# A lot of this extra knowledge courtesy of vimcasts.org!