Adapt to codegen type changes

[bmulholland]

dotansimha/graphql-code-generator#10479 proposes changes to type generation in a way that previously broke types used with this package. See also dotansimha/graphql-code-generator#10167

I don't recall what exactly was happening there, and haven't dug into whether this is still relevant, but wanted to give a heads up.

[bmulholland]

Might just be config/setup/docs changes necessary to resolve this, come to think of it.