landing page is very outdated

https://forge.rust-lang.org/index.html - the issue searches are incomplete (see https://rustc-dev-guide.rust-lang.org/getting-started.html#easy-or-mentored-issues for a more complete filter; probably we should move that from the dev-guide to forge? or remove forge's "help wanted" section altogether?) - many repositories are missing (and conversely, www.rust-lang.org is *really* not what we should suggest as a good first issue) - "no tools breakage week" i guess technically exists but probably doesn't need to be front and center, i don't know when we would ever need to break the documentation - it would be nice to link to more resources here (at least rustc-dev-guide and std-dev-guide, maybe others)