Fix incorrectly documented QueryResponse type in typescript.mdx

[ashishpandey001]

As per the index.d.ts file and in general how query responses are shaped the QueryResponse type is correctly typed as:

export type QueryResponse<E extends Entity<any, any, any, any>> = {
  data: EntityItem<E>[];
  cursor: string | null;
};

though in the docs reference it was typed as:

export type QueryResponse<E extends Entity<any, any, any, any>> = {
  data: EntityItem<E>;
  cursor: string | null;
};

Notice the data: EntityItem<E>[] in the declaration file vs data: EntityItem<E> in the docs.
This kinda confused me and hence this docs correction.

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