Redirect all pages from here to maintained docs and archive this repo

[nuke-web3]

https://substrate-developer-hub.github.io/docs/en/index is still up are high in searches above the maintained docs in some places

• Remove github pages deployments
• Setup redirect(s) so anything pointing here ends up trying a page on the main docs, perhaps getting re-redirected to a modern page
• Close PRs & Issues
• Actually archive this github repo in settings (not just a notice in the README

cc @lisa-parity @sacha-l not sure who is maintaining devhub these days, but docs team must care about this old old old version having better SEO than the present work. 😮‍💨