Document btcli list_delegates_lite and its API ref

[rajkaramchedu]

Document the list_delegates_lite subcommand and also update the API docs with updated docstrings. See: https://github.com/opentensor/bittensor/pull/1840/files

cc: @garrett-opentensor, @RomanCh-OT

[rajkaramchedu]

Docstrings update on the staging branch of the bittensor repo: opentensor/bittensor#1890

Still todo: Doc site updates in CLI and API ref pages.