Add example for adding Sublime Text 3 as an editor

Sublime Text 3 has command-line helper utility that needs to be used to pass these options. See the documentation: http://docs.sublimetext.info/en/latest/command_line/command_line.html

arcanist-windows.rst

@@ -89,12 +89,18 @@ They should work for Git Bash and PowerShell as well.
 
           arc set-config editor "\"C:\Program Files (x86)\Notepad++\notepad++.exe\" -multiInst -nosession"
 
-      * Sublime:
+      * Sublime Text 2:
 
       .. code-block:: text
 
           arc set-config editor "\"C:\Program Files\Sublime Text 2\sublime_text.exe\" -w -n"
 
+      * Sublime Text 3:
+
+      .. code-block:: text
+
+          arc set-config editor "\"C:\Program Files\Sublime Text 3\subl.exe\" -w -n"
+
 #. At this point, you should be all set up. Follow the rest of the
    standard instructions for :ref:`configuring Arcanist
    <setting-up-arcanist>` to use our instance.