Update README.md with abigen dependency (#75)

README.md

@@ -18,6 +18,10 @@ You will also need to [install docker](https://docs.docker.com/get-docker/), and
 ```
 make build-contracts
 ```
+You will also need to [install abigen](https://geth.ethereum.org/docs/tools/abigen) if you want to make changes to the smart contracts and then generate the go bindings 
+```
+make bindings
+```
 
 ## Running via make
 
@@ -114,4 +118,4 @@ When running on anvil, a typical log for the operator is
 [2024-04-09 18:25:10.679 PDT] INFO (logging/zap_logger.go:49) Signed task response header accepted by aggregator. {"reply":false}
 ```
 
-The error `task 2 not initialized or already completed` is expected behavior. This is because the aggregator needs to setup its data structures before it can accept responses. But on a local anvil setup, the operator had time to receive the websocket event for the new task, square the number, sign the response, and send it to the aggregator process before the aggregator has finalized its setup. Hence, the operator retries sending the response 2 seconds later and it is accepted.
+The error `task 2 not initialized or already completed` is expected behavior. This is because the aggregator needs to setup its data structures before it can accept responses. But on a local anvil setup, the operator had time to receive the websocket event for the new task, square the number, sign the response, and send it to the aggregator process before the aggregator has finalized its setup. Hence, the operator retries sending the response 2 seconds later and it is accepted.