Clarify docs on context-based store value propagation behavior during SSR

[juan-db]

Further discussion can be found in this issue #8282.

My interpretation of the current documentation is that changes to the value of the store won't ever propagate if the page is rendered server-side.
The sentence about hydration at the end of the paragraph does technically challenge this interpretation, but I believe the updated version is much clearer about the behavior.

If any of the terminology is incorrect, feel free to correct it. I'm especially unsure about the use of "CSR". I'm not sure if this is technically "hydration" or something else.

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[dummdidumm]

Tweaked some more - thank you!