Adds title to the rest of the files in activerecord/lib

activerecord/lib/active_record/transactions.rb

@@ -11,7 +11,8 @@ class TransactionError < ActiveRecordError # :nodoc:
     included do
       define_callbacks :commit, :rollback, :terminator => "result == false", :scope => [:kind, :name]
     end
-
+    # = Active Record Transactions
+    #
     # Transactions are protective blocks where SQL statements are only permanent
     # if they can all succeed as one atomic action. The classic example is a
     # transfer between two accounts where you can only have a deposit if the
@@ -19,7 +20,8 @@ class TransactionError < ActiveRecordError # :nodoc:
     # the database and guard the data against program errors or database
     # break-downs. So basically you should use transaction blocks whenever you
     # have a number of statements that must be executed together or not at all.
-    # Example:
+    #
+    # For example:
     #
     #   ActiveRecord::Base.transaction do
     #     david.withdrawal(100)

activerecord/lib/active_record/validations.rb

 module ActiveRecord
+  # = Active Record Validations
+  #
   # Raised by <tt>save!</tt> and <tt>create!</tt> when the record is invalid.  Use the
   # +record+ method to retrieve the record which did not validate.
+  #
   #   begin
   #     complex_operation_that_calls_save!_internally
   #   rescue ActiveRecord::RecordInvalid => invalid