@ChrSt well it is an overleaf alternative too, the first-party editor is pretty great :p but yeah, it's more of a "latex and overleaf alternative"
there's also an online package registry: https://typst.app/universe/
which you can use in documents with a simple
#import "@preview/<package_name>"
you can also use it locally in e.g. vscode with the tinymist extension, that has smarter tools than the official editor