Document what innerSignature (and signature) is for each keytype

[onbjerg]

I've come to learn that UserOp.signature can be e.g. abi.encode(r, s, v), abi.encode(r, vs) for secp256k1. The second case only if the privkey corresponds to UserOp.eoa. It would be nice to document exactly what signature can be, for which keytypes and under what constraints, as well as what innerSignature can be in the case where signature is abi.encodePacked(bytes(innerSignature), bytes32(keyHash), bool(prehash))

[atarpara]

Key Type	Key Hash	PreHash	Inner Signature
EOA Private Key	bytes32(0x00)	ignore	(r, s, v) for secp256k1 or (r, vs) for secp256k1 (only if private key corresponds to UserOp.eoa)
P256	bytes32(keyType, publicKey)	0	(r, s)
WebAuthN	bytes32(keyType, publicKey)	0 or 1	(r, s)
secp256k1	bytes32(keyType, publicKey)	0	(r, s) or (r, vs)