define some constants in typescript declaration file

[kaktus40]

Hello,
In the code, you defined some named numbers that could be used in twgl. I think that you should add these named values in the typescript declaration file:
instead of internalFormat?: number; in line 154 you could declare
internalFormat?:internalFormatType
ẁith
export type internalFormatType = 'R8' | 'R32F' | 'R16UI' | 'R16I' | 'R32UI' | 'R32I' | 'RG8' | 'RG32F' | 'RG16UI' | 'RG16I' | 'RG32UI' | 'RG32I' | 'RGB8' | 'RGB32F' | 'RGB16UI' | 'RGB16I' | 'RGB32UI' | 'RGB32I' | 'RGBA8' | 'RGBA32F' | 'RGBA16UI' | 'RGBA16I' | 'RGBA32UI' | 'RGBA32I'; for example