Link to Elm package documentation is broken

[j-maas]

In the Basics section, the link to the Elm package documentation (https://github.com/elm-lang/elm-package) is broken; it simply states that the repo has been merged with elm/compiler.

Unfortunately I could not find the documentation anymore, so I'm not sure how this can be dealt with.

[j-maas]

I've opened an issue on the package.elm-lang.org repo: elm/package.elm-lang.org#325