Fix typos in docs for ActiveRecord::Core::arel_table [ci skip]

activerecord/lib/active_record/core.rb

@@ -127,12 +127,10 @@ def ===(object)
         object.is_a?(self)
       end
 
-      # Returns an instance of +Arel::Table+ loaded with the current
-      # table name
+      # Returns an instance of Arel::Table loaded with the current table name.
       #
       #   class Post < ActiveRecord::Base
       #     scope :published_and_commented, published.and(self.arel_table[:comments_count].gt(0))
-      #     end
       #   end
       def arel_table
         @arel_table ||= Arel::Table.new(table_name, arel_engine)