add IBC relayers to chain.json

[Ertemann]

I propose adding a section relayers to the chain.json with the following structure so to provide clarity on active operators.

This combined with #1488 should provide all required info regarding IBC channels and their operational status between the various cosmos chains.

Data for both of these issues could be pulled from: https://github.com/SmartStake/relayers

{
  "$schema": "../chain.schema.json",
  "chain_name": "cosmos hub",
  
  "filler_content": "......",
  
  
  "relayers": [
    {
      "moniker": "lavender.Five Nodes",
	  "address": "cosmos18xrruhq5r246mwk0yj9elnn3mte8xa9uq4mdvu"
    },
    {
      "moniker": "cryptocrew",
	  "address": "cosmos1yvejj22t78s2vfk7slty2d7fs5lkc8rnnt3j9u"
    },
    {
      "moniker": "stakelab",
	  "address": "cosmos1mjq48r6435aewerpruwc8up3tz3rzan2ve7hp4"
    },
  ]
}

[JeremyParish69]

There have been a number of attempts at a 'relayer registry', although I'm not sure if any has risen to become the canon.
Including this here might introduce a lot of PR overhead.
If included here, I'd suggest that it be in the ibc files--not in the chain files.