WASM example

[memononen]

It would be nice to have a live example the users could just click and try.

[ApoorvaJ]

I have WASM compiling in a dev branch. I also had to add an API to add fonts to a font collection with a data pointer instead of file paths, in order to make it work with WASM. I will send a PR.

[memononen]

Just saw that commit, looks like great addition.