Fix few typos and improve markup at some levels

activemodel/lib/active_model/errors.rb

@@ -7,7 +7,7 @@ module ActiveModel
   # == Active \Model \Errors
   #
   # Provides a modified +Hash+ that you can include in your object
-  # for handling error messages and interacting with Action Pack helpers.
+  # for handling error messages and interacting with Action View helpers.
   #
   # A minimal implementation could be:
   #
@@ -279,7 +279,7 @@ module ActiveModel
     # If +message+ is a proc, it will be called, allowing for things like
     # <tt>Time.now</tt> to be used within an error.
     #
-    # If the <tt>:strict</tt> option is set to true will raise
+    # If the <tt>:strict</tt> option is set to +true+, it will raise
     # ActiveModel::StrictValidationFailed instead of adding the error.
     # <tt>:strict</tt> option can also be set to any other exception.
     #

activemodel/lib/active_model/lint.rb

@@ -13,7 +13,7 @@ module ActiveModel
     #
     # These tests do not attempt to determine the semantic correctness of the
     # returned values. For instance, you could implement <tt>valid?</tt> to
-    # always return true, and the tests would pass. It is up to you to ensure
+    # always return +true+, and the tests would pass. It is up to you to ensure
     # that the values are semantically meaningful.
     #
     # Objects you pass in are expected to return a compliant object from a call

activemodel/lib/active_model/secure_password.rb

@@ -9,7 +9,7 @@ module ActiveModel
 
     module ClassMethods
       # Adds methods to set and authenticate against a BCrypt password.
-      # This mechanism requires you to have a password_digest attribute.
+      # This mechanism requires you to have a +password_digest+ attribute.
       #
       # Validations for presence of password on create, confirmation of password
       # (using a +password_confirmation+ attribute) are automatically added. If

activemodel/lib/active_model/serialization.rb

@@ -128,7 +128,7 @@ module ActiveModel
       # retrieve the value for a given attribute differently:
       #
       #   class MyClass
-      #     include ActiveModel::Validations
+      #     include ActiveModel::Serialization
       #
       #     def initialize(data = {})
       #       @data = data