It lets us bundle static files such as images.
Allows us to `imports img from "./img.png"` to retrieve an image's path.
Note that we'll have to add other entries in the global.d.ts file if we
want to handle other extensions than .png.
Adds mocks to Jest tests so that we don't fail tests when loading static
assets.
catloversg
Tom Prince
JP Sugarbroad
Martin Fournier
Olivier Gagnon