fix link in the README.md
fix link in the README.md

TOTBWF/FSharp.Data.GraphQL,johnberzy-bazinga/FSharp.Data.GraphQL,OlegZee/FSharp.Data.GraphQL,alexpantyukhin/FSharp.Data.GraphQL,TOTBWF/FSharp.Data.GraphQL,johnberzy-bazinga/FSharp.Data.GraphQL,bazingatechnologies/FSharp.Data.GraphQL