📝 Docs: Deprioritize "ℹ️ New Documentation Site" from docs site?

### Documentation Request Checklist - [x] I have read and agree to Mocha's [Code of Conduct](https://github.com/mochajs/mocha/blob/main/.github/CODE_OF_CONDUCT.md) and [Contributing Guidelines](https://github.com/mochajs/mocha/blob/main/.github/CONTRIBUTING.md) - [x] I have searched for [related issues](https://github.com/mochajs/mocha/issues?q=is%3Aissue) and [issues with the `faq` label](https://github.com/mochajs/mocha/issues?utf8=%E2%9C%93&q=is%3Aissue%20label%3Afaq%20), but none matched my issue. - [x] I want to provide a PR to resolve this ### Overview We've had this callout on the homepage for many months now: https://github.com/mochajs/mocha/blob/b80d44b3bea01cb4cd7e0bda295ea00a1d6e157d/docs/src/content/docs/index.mdx?plain=1#L17-L26 Even ignoring the v12 release coming up, I think it's been around long enough that we can at least move it down on the page. I don't think users coming to the site still need it. How about we move it to the bottom of the homepage, and rephrase a bit? Maybe just: > ℹ️ New Documentation Site > > For the old docs website, see: [legacy.mochajs.org](https://legacy.mochajs.org). ### Additional Info I considered suggesting removing it altogether. But I think having _some_ link to the old legacy.mochajs.org website would be good. We have a lot of legacy users.