Add more detailed explanation to the doc, about use of React's Context API under <Outlet /> descendants

[plumbdataio]

I tried to use createContext/useContext to pass context from parent to a descendant which was under multiple <Outlet /> nests, but it didn't work and useContext() only gave me undefined value.

Now I understand what I needed to do was either:

1. Relaying context through outlet's context prop (ex. doing <Outlet context={useOutletContext()}> in the multiple Outlets in the middle)
2. Passing context through UNSAFE_RemixContext instead of createContext()'s return value

but both of which was not intuitive to me because, I need to relay contexts although React's context API should be there to avoid "relaying" props, or I need to use utility class with UNSAFE_ prefix (and I have no idea why and how it's "unsafe"...).

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The real problem is that there is no documentation or issues which cleary mention that 'useContext() will return undefined if you're trying to pass context to the descendant under the '.

So my sugestion here is adding it to the document, somewhere like in this page.
It must be helpful as I thing there might be folks like me who wandered on the internet because of this...

*Please collect me if something above is wrong and my research was not enough

Thanks,