Update docs to document peer support in network status response

[linconvidal]

Task context

• Peers list was added to /network/status response in v.1.3.2 release. We need to document the behavior, flag usage and API specs.

Task checklist

• Document PEER_DISCOVERY flag in env vars page, with explanation of behaviors
• Document api docs for /network/status response
  • Replace btc placeholders with Cardano examples (hosts, ports, network identifiers, etc)
  • Add examples for peer list responses and typical values seen in preprod/mainnet
  • Add specification for "minItems: 1" (this will be checked by schema verification)

[Kartiiyer12]

Not enabling for 1.4.0