`Query` not being extended

[MrSaints]

It seems Graphene Federation has stopped returning an SDL with extend type Query, and instead returns type Query. I'm not sure if this is intentional, but it is not compatible with some implementations of Federation Gateway.

See diff: https://github.com/graphql-python/graphene-federation/pull/4/files#diff-3111b5ad3ddd7af276c62d4c15988d6c6f3ee13f1b6eaa87725f4fe94cc65867L42-L43

(EDIT: It seems perhaps it was never included by default)

Other Federation implementation seems to include this, e.g. gqlgen (Go): https://github.com/99designs/gqlgen/blob/2d8673a691deffe6ddd1f4d5f013a52dc91aef91/plugin/federation/federation.go#L223, Ariadne (Python) https://github.com/apollographql/apollo-federation-subgraph-compatibility/blob/1bc1ddd56c796f2a7ff9256d279c7780dd48f582/implementations/ariadne/schema.graphql#L65

Apollo docs seems to suggest it too, but to be honest, it's not too clear. Let me know what y'all think.