Adds a new event 'paused_for_user' when the printer needs manual intervention
echo:busy: paused for user is received on the serial port, this plugin then raises a
paused_for_user event, which may then be used with other plugins like OctoPrint-MQTT to alert the user, that the printer needs attention.
The primary use for this is the Prusa MMU2S, which when it fails to load/unload filament, will halt the printer and send this message on serial.
See the plugin’s README for details.