Update docs site design after review (#595)
* Update typography colours
All headings are now #444444 (heading)
All sidebar/legend items are now #444444 (passive)
* Fix jumpy legend position
* Fix stripes and sidebar layout
* Reduce font-size on mobile to 15px effectively
* Add sidebar collapsing sections and active styling
* Update sidebar size and padding
* Fix links in mdx using react-router-dom Link
* Fix Loading page design
* Add basic implementation for <ScrollToTop />
* Fix internal links on index pages
This will need further fixes in the plugin
* Fix internal links on /docs/
* Update react-static-plugin-md-pages to fix lost state
* Add usePrefetch hook to home screen to increase load consistency
* Upgrade react-static-plugin-md-pages to fix page update
* Add missing suspense rethrow to custom catch code
* update <Loading /> so that it isn't affected by throws/suspense
* remove duplicate <Article /> parts
* WIP: enable the 404 page on the built app
* Upgrade react-static-plugin-md-pages to remove page data requirement
* Fix path resolution for internal links properly
* Fix homepage links in staging and add link to logo
* Fix local relative internal links on same level
* fix markdown links from other pages
* Fix several hash anchor links
Co-authored-by: Will Golledge <will.golledge@formidable.com>
Co-authored-by: wgolledge <wiggiumg@gmail.com>