In this PR:
1. Implement deployment script for all contracts involved. This includes
1. EigenLayer core contracts.
2. Snowbridge contracts.
3. Our custom contracts to interact with both protocols.
4. Update README to document functionalities of `contracts` directory.
Future work:
1. Deployment of EigenLayer contracts should be conditional, as we
wouldn't deploy them in testnet or mainnet, but we would do it in an
internal stagenet.
5. Cleaning up unused smart contracts.