Improve agent operations experience using Docker

[nambrot]

Block on #1848

• CONFIG_FILES is unclear what the relative path is in the docker image
  • becomes superflous with #1687 and https://github.com/hyperlane-xyz/hyperlane-monorepo/issues/1850
• Should mention how to mount config files into the container
• Add docker-compose flow

[asaj]

@nambrot if we make DESTINATION_CHAINS required then CONFIG_FILES becomes optional and you would only use it to point to PI config, which makes this not a thing:

CONFIG_FILES is unclear what the relative path is in the docker image

[nambrot]

Great call out, capturing that insight

[mattiekat]

https://app.gitbook.com/o/Pl1c4GYUuMTxkQTcVCdO/s/STktvmwamt5GXWv1jqOM/~/changes/108