Clarify that abstract types are supported by `loads:`
Clarify that abstract types are supported by `loads:`

rmosolgo/graphql-ruby,rmosolgo/graphql-ruby,nevesenin/graphql-ruby,nevesenin/graphql-ruby,nevesenin/graphql-ruby,xuorig/graphql-ruby,rmosolgo/graphql-ruby,xuorig/graphql-ruby,rmosolgo/graphql-ruby,nevesenin/graphql-ruby,xuorig/graphql-ruby