🛠 Repo: Pull in @mocha/docdash updates

[JoshuaKGoldberg]

Tooling Suggestion Checklist

• I have tried restarting my IDE and the issue persists.
• I have pulled the latest master branch of the repository.
• I have read and agree to Mocha's Code of Conduct and Contributing Guidelines
• I have searched for related issues and issues with the faq label, but none matched my issue.
• I want to provide a PR to resolve this

Overview

Right now, tooling for the docs site is built on a @mocha/docdash package:

https://github.com/mochajs/mocha/blob/9f9917822fa1d3fe2ec2867809cbbf86f4165f0c/package.json#L78
https://github.com/mochajs/mocha/blob/6d3fe26b2f41edfec4647f53e01cfba3b8eadd09/jsdoc.conf.json#L6

That package comes from https://github.com/mochajs/docdash: a fork of the https://github.com/clenemt/docdash JSDoc 3 theme. Right now it's "54 commits ahead of, 89 commits behind clenemt/docdash:master".

The theme seems to be working fine but has a dependency on taffydb flagged by mochajs/mocha#5070. We should pull in upstream updates to the fork so that the latest clenemt/docdash fixes+features are available.

Filing this issue to track here. We'll want to also file an issue on the mochajs/docdash repo. mochajs/mocha-docdash#18

Additional Info

I suppose un-forking is theoretically doable too, but it seems like there are a lot of customizations on the Mocha side.

[mark-wiemer]

Note that this will not be necessary with the new site, mochajs/mocha#5576

[JoshuaKGoldberg]

Ah, yes, we can transfer this over to https://github.com/mochajs/docs-legacy. I'll do that now.