docs: add documentation on channel identifier, closes supabase#18 (su…

…pabase#19)

* docs: add documentation on chanenl_name identifier, closes supabase#18

* docs: add :heartbeat_interval docs

* chore: version bump

* feat: make connection parameters optional

chore: publish to hex.pm workflow (supabase#15)

fix: Change URLs in Readme and fix example (supabase#13)

fix: Add ex doc which is required for publish (supabase#12)