Update docs for v0.7

[PaulLeCam]

Mostly docs fixes and generated APIs updates, the main content change is about the directives to add the SET account relation and the accountRelationFields.

A small functional change as well is defaulting the shouldIndex to true when calling the set<Model> mutations, so unless the shouldIndex option is explicitly set to false, the document should be indexed, I think this behavior would better match the expectations.

[m0ar]

Psst, missing information about the @immutableFields directive in the schema definition language. Seems it's only mentioned in the devtools 👼