Make /releases/X.X.X an alias for https://blog.rust-lang.org/XXXX/XX/XX/Rust-X.X.X.html

It would make it easier to find the blog post announcing a particular release. I'm not sure how technically feasible this is since this is a static site, so perhaps this should be under rust-lang/www.rust-lang.org? The downside of that, though, is that one may need to open two PRs; one for the blog and one for the website alias.