Configuration for connecting to a Home Assistant instance.
Build the WebSocket URL from a base HA URL.
@type t() :: %Hassock.Config{token: String.t(), url: String.t()}
@spec websocket_url(t()) :: String.t()
Converts http:// to ws:// and https:// to wss://, and appends /api/websocket.
http://
ws://
https://
wss://
/api/websocket