Mark this repo deprecated?

[Rich-Harris]

I'm not personally able to devote any time to maintaining this project. @adrianheine and others — should we mark the repo (and package?) as deprecated so that people aren't misled?

Prompted by mrdoob/three.js#17276 (comment)

[mourner]

In short, no — see my response on that ticket mrdoob/three.js#17276 (comment)

What we could do is add a note at the top of the readme that manages expectations — e.g. stating that the project is in maintenance mode, meaning we will accept PRs for bug fixes and do corresponding patch releases, but will not work on or accept PRs for major features such as async/await or class fields. See an example of such a note at the top of this repo https://github.com/documentationjs/documentation

[Rich-Harris]

Good idea — #221