made the shell include the documentation library automatically

lib/shutil.lua

@@ -2,6 +2,7 @@ local component = require "component"
 local fs = require "fs"
 local shell = require "shell"
 local ed = require "ed"
+local doc = require "doc"
 local shutil = {}
 shutil.ed = ed.interactive
 shutil.vi = ed.visual