Web build support

[henkehedstrom]

Firstly I would like to say that it's awesome to be able to use imgui so easily in godot. I don't know how much work it took for you to implement it but thank you! I read in the docs that this plugin only supports: Windows (x64), macOS (x64/arm64), and Linux (x64). It would be really nice if I could use it in web builds aswell.

I'm not sure if this is easy or not but I just wanted to let you guys that it is something wanted (at least by me). Thanks again!