[Request] document for Piu ImageBuffer

[stc1988]

piu.md explain how to display bundled image resources with Image, but ImageBuffer does not seem to be documented in piu.md.

ImageBuffer is useful when displaying image data obtained at runtime, for example camera frames or downloaded/decoded JPEG artwork. In those cases the image is not a Resource, so Image is not the right fit.

It would be helpful to add a short ImageBuffer section covering:

• when to use ImageBuffer
• required fields such as imageWidth and imageHeight
• setting buffer to update the displayed image
• a small example, possibly based on examples/io/imagein/camera/camera-test/main.js

Thanks.

[phoddie]

Sure, we'll look at updating the docs.

By the way, this was a good reminder that we are also missing the TypeScript declarations for ImageBuffer. I've added that. TypeScript declarations are a kind of documentation. ;)