The intellij-elm plugin now has a new home, under the elm-tooling organization! 
- GitHub: GitHub - elm-tooling/intellij-elm: Elm plugin for IntelliJ Platform IDEs
- JetBrains Marketplace: https://plugins.jetbrains.com/plugin/27831-elm-language
- In your IDE: Install the one called “Elm Language” by Elm Tooling, v5.1.0.
I was given access to the Elm Tooling GitHub organization by Kolja Lampe, and then forked the plugin and invited collaborators. Andrew Hankinson then did most of the hard work setting things up, publishing the plugin and fixing things. Andi Pabst did lots of great contributions, along with a few more contributors.
Unfortunately we had to fork the GitHub repo (so issues aren’t transferred, but it might be good to start from a clean slate anyway), and we also had to publish a new plugin (which might make things a bit confusing for beginners). This time around, multiple people have access to the GitHub repo and the plugin in the JetBrains Marketplace, and we intend to hand things over as the current maintainers’ lives change.
If you want to contribute, you are more than welcome! We chat about development in the Incremental Elm Discord in the #intellij-elm channel.