Spawnable scenes can be configured in the editor or through code (see [method add_spawnable_scene]).
Also supports custom node spawns through [method spawn], calling [method _spawn_custom] on all peers.
Internally, [MultiplayerSpawner] uses [method MultiplayerAPI.object_configuration_add] to notify spawns passing the spawned node as the [code]object[/code] and itself as the [code]configuration[/code], and [method MultiplayerAPI.object_configuration_remove] to notify despawns in a similar way.
Method called on all peers when a custom spawn was requested by the authority using [method spawn]. Should return a [Node] that is not in the scene tree.
[b]Note:[/b] Spawned nodes should [b]not[/b] be added to the scene with `add_child`. This is done automatically.
Adds a scene path to spawnable scenes, making it automatically replicated from the multiplayer authority to other peers when added as children of the node pointed by [member spawn_path].
Requests a custom spawn, with [code]data[/code] passed to [method _spawn_custom] on all peers. Returns the locally spawned node instance already inside the scene tree, and added as a child of the node pointed by [member spawn_path].
[b]Note:[/b] Spawnable scenes are spawned automatically. [method spawn] is only needed for custom spawns.
