Add a simple README
Add a simple README

Mantle/MTLManagedObjectAdapter,Mantle/MTLManagedObjectAdapter,samkhawse/MTLManagedObjectAdapter,Mantle/MTLManagedObjectAdapter,ServiceNow/MTLManagedObjectAdapter,ServiceNow/MTLManagedObjectAdapter,ServiceNow/MTLManagedObjectAdapter,samkhawse/MTLManagedObjectAdapter,samkhawse/MTLManagedObjectAdapter,redengineer/MTLManagedObjectAdapter,redengineer/MTLManagedObjectAdapter,redengineer/MTLManagedObjectAdapter