Allowing type augmentation

[addlistener]

Is your feature request related to a problem? Please describe.
When using custom & info we'd like to supply our own typing. However they sits in a type alias instead of an interface so can cannot using type augmentation ( as state here https://www.typescriptlang.org/docs/handbook/2/everyday-types.html#differences-between-type-aliases-and-interfaces )

Describe the solution you'd like
Change type to interface for UserComponentConfig & NodeData & Node.

[prevwong]

Good suggestion, care to submit a PR?

[addlistener]

Sure but not at the moment. Still in some projects and feeling out of stamina.

Something that can also be fixed is the lack of documentation of info.

And I gotta say the API of craft.js is minimal and of good taste. Enjoying every minute playing with it.