Add link to canvas-displayin the README

[rambip]

I just discovered canvas-display after hours of searching for a way to write raw data to a canvas in rust.

It seems to work really well, and without boilerplate. i think this is is a killer feature of your crate (assuming the performance is not terrible) and the page isn't mentioned in your readme ?

This API could provide a great way to draw to a canvas in webassembly (since there is still no standard, and web frameworks doesn't provide solutions). Everyone looking for sending pixels to a screen in webassembly should be aware of this API.

[jamwaffles]

Well spotted! I've seen it pop up in the dependents list on crates.io. I'd be happy to have it listed in the README and lib.rs docs if you want to open a PR to add the link in.