fix bad format [ci skip]

activemodel/lib/active_model/model.rb

@@ -2,11 +2,11 @@ module ActiveModel
 
   # == Active Model Basic Model
   #
-  # Includes the required interface for an object to interact with +ActionPack+,
-  # using different +ActiveModel+ modules. It includes model name introspections,
+  # Includes the required interface for an object to interact with <tt>ActionPack</tt>,
+  # using different <tt>ActiveModel</tt> modules. It includes model name introspections,
   # conversions, translations and validations. Besides that, it allows you to
   # initialize the object with a hash of attributes, pretty much like
-  # +ActiveRecord+ does.
+  # <tt>ActiveRecord</tt> does.
   #
   # A minimal implementation could be:
   #
@@ -19,8 +19,8 @@ module ActiveModel
   #   person.name # => 'bob'
   #   person.age # => 18
   #
-  # Note that, by default, +ActiveModel::Model+ implements +persisted?+ to
-  # return +false+, which is the most common case. You may want to override it
+  # Note that, by default, <tt>ActiveModel::Model</tt> implements <tt>persisted?</tt> to
+  # return <tt>false</tt>, which is the most common case. You may want to override it
   # in your class to simulate a different scenario:
   #
   #   class Person
@@ -35,7 +35,7 @@ module ActiveModel
   #   person = Person.new(:id => 1, :name => 'bob')
   #   person.persisted? # => true
   #
-  # Also, if for some reason you need to run code on +initialize+, make sure you
+  # Also, if for some reason you need to run code on <tt>initialize</tt>, make sure you
   # call super if you want the attributes hash initialization to happen.
   #
   #   class Person
@@ -52,7 +52,7 @@ module ActiveModel
   #   person.omg # => true
   #
   # For more detailed information on other functionalities available, please refer
-  # to the specific modules included in +ActiveModel::Model+ (see below).
+  # to the specific modules included in <tt>ActiveModel::Model</tt> (see below).
   module Model
     def self.included(base)
       base.class_eval do