Add note about using amount when committing

Signed-off-by: Sasha Bogicevic <[email protected]>

Author: v0d1ch

docs/docs/how-to/incremental-commit.md

@@ -49,6 +49,11 @@ cardano-cli query utxo \
   --out-file commit-utxo.json
 ```
 
+:::info
+You can also specify `amount` of lovelace you want to commit together with the `UTxO` and hydra-node would
+commit only the specified amount and return any leftover to the user address.
+:::
+
 Then a request to the `/commit` endpoint provides us with a transaction:
 
 ```shell