Ok for me to add this, just two remarks:

1. We should then add it to Core, too.
2. IMHO, in the docs, we should rather promote the practice of creating explicit bindings using globalThis, like

@scope("globalThis")
external window: option<Dom.window> = "window"

instead of using

Js.globalThis["window"]

at least Js.globalThis["window"] is better than %raw("window") 😉

We should then add it to Core, too.

We already have in https://github.com/rescript-association/rescript-core/blob/22642ea/src/RescriptCore.res#L49, but there is a mismatch in the window usecase

Reported to rescript-lang/rescript-core#240

I'm merging this, globalThis already in the Core with the same signature