Hidden macros explainer

[catmcgee]

Could we also include an explaiantion for hidden "macros" (things we inject within a user's noir contract without them having to explicitly write a macro). One example that you all are aware of is adding compute_note_hash_and_nullifier() . There are several of these.

another one - the way we generate a contract interface by default now to make calls to a function within the contract much nicer