Suggestion: Mention changes needed for tutorial to work in [current year]

[avelican]

The tutorial is a bit out of date, and there's a few small changes that need to be made for it to work.

One is that innerRef is changed to ref.

Another is that props passed to styled-components (e.g. isDragging) must be prefixed with dollar sign ($isDragging), otherwise they'll be passed to React, which doesn't like DOM elements having props and will give an error.

(This has to do with styled-components, rather than dnd, though I ran into it while following the tutorial for dnd, which uses styled-components, so it's worth mentioning too.)

I suggest creating such a page in the docs with the latest errata for this tutorial and linking to it above/below the link to the tutorial.