docs: Restructure old docs in preparation of new docs site (#9154)
* add temp banner to stately
* add banner to all pages
* move react spectrum pages to v3
* move releases under v3
* make sure intro and concept pages appear in sidebar for v3
* move stately hooks to aria and remove uneeded aria hooks
* lint
* test redirect
* add redirect pages for v3 and releases
* fix redirects for intro and concepts pages
* add redirects for react aria
* redirect release index page and rename script for consistency
* add redirects for blog and internationalized
* get rid of chevron
* properly redirect examples and point to new concepts page
* update more redirects
* have both stately and aria hooks in sidenav for react stately too
* rename sidebar headers
* add redirects for the remaining Foundation section pages
* Remove redirect pages. Will handle in CDN instead.
* Remove old docs that we migrated
* Update URL structure
* Update URLs
* Build old docs as part of s2 build
* Add stage docs build
* Remove RedirectLayout
* Fix more URLs
* Fix more URLs
* Remove Dialog from DatePicker examples
* More broken links
* Fix broken links
* More links
* Open search menu on components link at bottom of homepage
Also fix more links
* update migration banner
* make react spectrum links relative and bring back s2 gradient
* create relative links for aria and stately hook banner
* remove banner from releases and fix filetrigger link
* Fix one more url
* Move Support page to v3
* Remove unused useStepList docs
* Fix links
* Fix separator link
* Fix useDialog links
* Fix stately links from migration banner
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Co-authored-by: Devon Govett <devongovett@gmail.com>