chore(docs): update migration notes

docs/docs/misc/migration_notes.md

@@ -6,15 +6,36 @@ keywords: [sandbox, cli, aztec, notes, migration, updating, upgrading]
 
 Aztec is in full-speed development. Literally every version breaks compatibility with the previous ones. This page attempts to target errors and difficulties you might encounter when upgrading, and how to resolve them.
 
-## 0.28.0
+## 0.30.0
+### [AztecJS] Simplify authwit syntax
+```diff
+- const messageHash = computeAuthWitMessageHash(accounts[1].address, action.request());
+- await wallets[0].setPublicAuth(messageHash, true).send().wait();
++ await wallets[0].setPublicAuthWit({ caller: accounts[1].address, action }, true).send().wait();
+```
+
+```diff
+const action = asset
+    .withWallet(wallets[1])
+    .methods.unshield(accounts[0].address, accounts[1].address, amount, nonce);
+-const messageHash = computeAuthWitMessageHash(accounts[1].address, action.request());
+-const witness = await wallets[0].createAuthWitness(messageHash);
++const witness = await wallets[0].createAuthWit({ caller: accounts[1].address, action });
+await wallets[1].addAuthWitness(witness);
+```
 
-### Automatic NoteInterface implementation and selector changes
+Also note some of the naming changes:
+`setPublicAuth` -> `setPublicAuthWit`
+`createAuthWitness` -> `createAuthWit`
+
+### [Aztec.nr] Automatic NoteInterface implementation and selector changes
 
 Implementing a note required a fair amount of boilerplate code, which has been substituted by the `#[aztec(note)]` attribute. 
 
 Before:
 
-```rust
+```diff
++ #[aztec(note)]
 struct AddressNote {
     address: AztecAddress,
     owner: AztecAddress,
@@ -23,23 +44,23 @@ struct AddressNote {
 }
 
 impl NoteInterface<ADDRESS_NOTE_LEN>  for AddressNote {
-    fn serialize_content(self) -> [Field; ADDRESS_NOTE_LEN]{
-        [self.address.to_field(), self.owner.to_field(), self.randomness]
-    }
-
-    fn deserialize_content(serialized_note: [Field; ADDRESS_NOTE_LEN]) -> Self {
-        AddressNote {
-            address: AztecAddress::from_field(serialized_note[0]),
-            owner: AztecAddress::from_field(serialized_note[1]),
-            randomness: serialized_note[2],
-            header: NoteHeader::empty(),
-        }
-    }
-
-    fn compute_note_content_hash(self) -> Field {
-        pedersen_hash(self.serialize_content(), 0)
-    }
-
+-    fn serialize_content(self) -> [Field; ADDRESS_NOTE_LEN]{
+-        [self.address.to_field(), self.owner.to_field(), self.randomness]
+-    }
+-
+-    fn deserialize_content(serialized_note: [Field; ADDRESS_NOTE_LEN]) -> Self {
+-        AddressNote {
+-            address: AztecAddress::from_field(serialized_note[0]),
+-            owner: AztecAddress::from_field(serialized_note[1]),
+-            randomness: serialized_note[2],
+-            header: NoteHeader::empty(),
+-        }
+-    }
+-
+-    fn compute_note_content_hash(self) -> Field {
+-        pedersen_hash(self.serialize_content(), 0)
+-    }
+-
     fn compute_nullifier(self, context: &mut PrivateContext) -> Field {
         let note_hash_for_nullify = compute_note_hash_for_consumption(self);
         let secret = context.request_nullifier_secret_key(self.owner);
@@ -60,13 +81,13 @@ impl NoteInterface<ADDRESS_NOTE_LEN>  for AddressNote {
         ],0)
     }
 
-    fn set_header(&mut self, header: NoteHeader) {
-        self.header = header;
-    }
-
-    fn get_header(note: Self) -> NoteHeader {
-        note.header
-    }
+-    fn set_header(&mut self, header: NoteHeader) {
+-        self.header = header;
+-    }
+-
+-    fn get_header(note: Self) -> NoteHeader {
+-        note.header
+-    }
 
     fn broadcast(self, context: &mut PrivateContext, slot: Field) {
         let encryption_pub_key = get_public_key(self.owner);
@@ -80,56 +101,9 @@ impl NoteInterface<ADDRESS_NOTE_LEN>  for AddressNote {
         );
     }
 
-    fn get_note_type_id() -> Field {
-        6510010011410111511578111116101
-    }
-}
-
-```
-
-After:
-
-```rust
-#[aztec(note)]
-struct AddressNote {
-    address: AztecAddress,
-    owner: AztecAddress,
-    randomness: Field,
-}
-
-impl NoteInterface<ADDRESS_NOTE_LEN>  for AddressNote {
-    fn compute_nullifier(self, context: &mut PrivateContext) -> Field {
-        let note_hash_for_nullify = compute_note_hash_for_consumption(self);
-        let secret = context.request_nullifier_secret_key(self.owner);
-        // TODO(#1205) Should use a non-zero generator index.
-        pedersen_hash([
-            note_hash_for_nullify,
-            secret.low,
-            secret.high,
-        ],0)
-    }
-
-    fn compute_nullifier_without_context(self) -> Field {
-        let note_hash_for_nullify = compute_note_hash_for_consumption(self);
-        let secret = get_nullifier_secret_key(self.owner);
-        pedersen_hash([
-            note_hash_for_nullify,
-            secret.low,
-            secret.high,
-        ],0)
-    }
-
-    fn broadcast(self, context: &mut PrivateContext, slot: Field) {
-        let encryption_pub_key = get_public_key(self.owner);
-        emit_encrypted_log(
-            context,
-            (*context).this_address(),
-            slot,
-            Self::get_note_type_id(),
-            encryption_pub_key,
-            self.serialize_content(),
-        );
-    }
+-    fn get_note_type_id() -> Field {
+-        6510010011410111511578111116101
+-    }
 }
 ```