An event Lingo couldn't build a payload for, such as one whose shape
Discord changed. It never reaches Lingo.Bot.handle_event/2, whose
clauses expect the parsed payload; Lingo.Bot.handle_error/2 gets this
error with {event, data}, Discord's raw data with string keys.
exception is what parsing raised.
Summary
Types
@type t() :: %Lingo.EventError{ __exception__: true, data: term(), event: atom(), exception: Exception.t(), message: String.t() }