Don't pass SSRed code to the client

[avivkeller]

(Follow-up #285)

Currently, the web generator statically renders a large portion of the documentation, and then rehydrates it on the client. Most of this code doesn't change, and doesn't need to be rehydrated. We should find a way to avoid passing this to the client at all.

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Footnotes

1. Visual from https://www.gatsbyjs.com/docs/conceptual/partial-hydration/ ↩