feat: switch makefile -> justfile

[merklefruit]

• closes Migrate from Makefile to Just #30

Remember to install just: https://github.com/casey/just

Now it shows:

❯ just
Available recipes:
    default      # default recipe to display help information
    demo         # run the web demo locally
    up           # spin up the bolt devnet
    down         # turn down the bolt devnet and remove the enclave
    clean        # remove all kurtosis data and stop the engine
    restart      # restart the bolt devnet with updated docker images
    inspect      # show the running containers and port mappings for the bolt devnet
    relay-logs   # show the logs for the bolt devnet relay
    builder-logs # show the logs for the bolt devnet builder
    boost-logs   # show the logs for the bolt devnet mev-boost sidecar
    sidecar-logs # show the logs for the bolt devnet bolt-sidecar
    send-preconf # manually send a preconfirmation to the bolt devnet
    build-images # build all the docker images locally