Feat: [Minor] Outdated StarknetContract docstring #76

[Cevedale]

The docstring example was indeed incomplete, and I appreciate your keen observation. I've updated it to include the deploy_execution_info argument in the instantiation example, ensuring a more accurate and comprehensive representation of the class usage.

class StarknetContract:
"""
A high level interface to a StarkNet contract used for testing. Allows invoking functions.
Example:
contract_class = compile_starknet_files(...)
state = await StarknetState.empty()
contract_address = await state.deploy(contract_class=contract_class)
deploy_execution_info = ... # Obtain the deployment transaction execution info.
contract = StarknetContract(
state=state, abi=contract_class.abi, contract_address=contract_address,
deploy_execution_info=deploy_execution_info)

await contract.foo(a=1, b=[2, 3]).invoke()
"""

... (rest of the class remains unchanged)