Update module_ex.rb code documentation and code style

Didn't look good on rubydoc.info: http://i.imgur.com/469N92P.png

lib/liquid/module_ex.rb

@@ -7,16 +7,17 @@
 # to the allowed method passed with the liquid_methods call
 # Example:
 #
-# class SomeClass
-#   liquid_methods :an_allowed_method
+#   class SomeClass
+#     liquid_methods :an_allowed_method
 #
-#   def an_allowed_method
-#     'this comes from an allowed method'
+#     def an_allowed_method
+#       'this comes from an allowed method'
+#     end
+#
+#     def unallowed_method
+#       'this will never be an output'
+#     end
 #   end
-#   def unallowed_method
-#     'this will never be an output'
-#   end
-# end
 #
 # if you want to extend the drop to other methods you can defines more methods
 # in the class <YourClass>::LiquidDropClass
@@ -26,31 +27,33 @@
 #       'and this from another allowed method'
 #     end
 #   end
-# end
+#
 #
 # usage:
-# @something = SomeClass.new
+#   @something = SomeClass.new
 #
 # template:
-# {{something.an_allowed_method}}{{something.unallowed_method}} {{something.another_allowed_method}}
+#   {{something.an_allowed_method}}{{something.unallowed_method}} {{something.another_allowed_method}}
 #
 # output:
-# 'this comes from an allowed method and this from another allowed method'
+#   'this comes from an allowed method and this from another allowed method'
 #
 # You can also chain associations, by adding the liquid_method call in the
 # association models.
 #
 class Module
-
   def liquid_methods(*allowed_methods)
     drop_class = eval "class #{self.to_s}::LiquidDropClass < Liquid::Drop; self; end"
+    
     define_method :to_liquid do
       drop_class.new(self)
     end
+    
     drop_class.class_eval do
       def initialize(object)
         @object = object
       end
+      
       allowed_methods.each do |sym|
         define_method sym do
           @object.send sym
@@ -58,5 +61,4 @@ class Module
       end
     end
   end
-
 end