feat: Update with new interface

Give more context in the swap-encoder.md

propeller-swap-encoders/propeller_swap_encoders/balancer.py

@@ -1,6 +1,6 @@
 from typing import Any
 
-from core.encoding.interface import SwapStructEncoder
+from core.encoding.interface import SwapStructEncoder, EncodingContext
 from core.type_aliases import Address
 from eth_abi.packed import encode_abi_packed
 from hexbytes import HexBytes
@@ -8,18 +8,8 @@ from hexbytes import HexBytes
 
 class BalancerSwapStructEncoder(SwapStructEncoder):
     def encode_swap_struct(
-        self, swap: dict[str, Any], receiver: Address, exact_out: bool, **kwargs
+        self, swap: dict[str, Any], receiver: Address, encoding_context: EncodingContext
     ) -> bytes:
-        """
-        Parameters:
-        ----------
-        swap
-            The swap to encode
-        receiver
-            The receiver of the buy token
-        exact_out
-            Whether the amount encoded is the exact amount out
-        """
         return encode_abi_packed(
             ["address", "address", "bytes32", "address", "bool", "bool"],
             [
@@ -27,7 +17,7 @@ class BalancerSwapStructEncoder(SwapStructEncoder):
                 swap["buy_token"].address,
                 HexBytes(swap["pool_id"]),
                 receiver,
-                exact_out,
+                encoding_context.exact_out,
                 swap["token_approval_needed"],
             ],
         )