Layer - Supernote

Only note files (.note) have layer data. Other file types do not have layer data.

Field	Type	Description
`layerId`	`number`	Layer ID: - `-1` background layer: cannot delete, cannot rename, cannot reorder, cannot set as current layer, can set visibility - `0` main layer: cannot delete, cannot rename, can reorder, can set as current layer, can set visibility - `1-3` custom layers: can delete, can rename, can reorder, can set as current layer, can set visibility
`name`	`string`	Layer name
`isCurrentLayer`	`boolean`	Whether this is the current layer
`isVisible`	`boolean`	Whether this layer is visible