Typed element creation

[georgefst]

Would it be possible to add a method to IsElement for getting the element's tag? This would allow for safer element construction. I've ended up implementing this downstream, but it'd be tedious to do for the entire API:

createElementTyped :: forall a. (IsElement' a, PFromJSVal a) => Document -> JSM a
createElementTyped doc = unsafeCastTo pFromJSVal =<< createElement doc (elementTag @a)
class (IsElement a) => IsElement' a where
    elementTag :: Text
instance IsElement' HTMLCanvasElement where
    elementTag = "canvas"
instance IsElement' HTMLImageElement where
    elementTag = "img"
instance IsElement' HTMLLinkElement where
    elementTag = "link"