Fix typo in documentation for And.rb
Fix typo in documentation for And.rb

Change $or to $and in documentation for And.rb
Welovroi/mongoid,Welovroi/mongoid,jonhyman/mongoid,mongodb/mongoid,mongodb/mongoid,jonhyman/mongoid,herimedia/mongoid,kay-kim/mongoid,kay-kim/mongoid,mongodb/mongoid,herimedia/mongoid