Change rgbaArray type definition to a tuple

[acashjos]

Feature Request

More of a tiny typedef improvement suggestion.
I accidentally imported rgbaArray from index.d.ts of this module today, and noticed that its a ReadonlyArray<number>.
This type can have n number of items, while I'd expect an rgba type to have only 4 number items.

Code sample

Changing
export type rgbaArray = ReadonlyArray<number>;
to
export type rgbaArray =Readonly<[r:number, g: number, b: number, a: number]>;

[WoLewicki]

This type has been removed as a part of #1726, so I believe this is not a problem anymore. Thanks for your contribution though! I will close this issue. Feel free to comment here if something is wrong and we can always reopen it then.