Consider providing an IntelliJ plugin

I've been enjoying trying out Effekt! One annoying aspect is the lack of an IntelliJ plugin. I've been able to find ad-hoc ways to add syntax highlighting and even connect it to the LSP, but all of it has been inconsistent, especially in `effekt.md` documents. Providing more direct integration with IntelliJ (while still using LSP) may thus be desirable. I might prototype something for this soon, but I figured I should raise this issue to you. It may help adoption amongst JVM devs too.