Config file format

[benluelo]

Prior art:

• Hermes: https://github.com/informalsystems/hermes/blob/master/config.toml
• ibc-go relayer: https://github.com/cosmos/relayer/blob/main/cmd/config.go#L476

[cor]

Regarding the actual file format, I'd say go for JSON. I think JSON is still easiest for people to understand overall, allows people to use jq, and it's easy to go Nix -> JSON with the Nix stdlib.

TOML is nice for deeply nested configs, but I think that the relayer config will be pretty simple.

[benluelo]

JSON works for me, will likely be easier to understand than TOML anyways