can someone mention me a VS code plugin to code in minecraft scripted language (i am on Linux).
what does povstalec utilized to create his mods.

Up until a few days ago I used Eclipse IDE, but due to... special circumstances I started using IntelliJ IDE.

Don't actually consider using Eclipse. I love it, but it's super unsuitable for Minecraft modding, since a lot of things (especially the new stuff) just don't work with it properly.

how to set up IntelliJ like yours ?

I don't use any special setups, no plugins that help with writing code or any changes in keybinds, it's all default values.

The only thing I changed is the theme to an Eclipse theme I downloaded, because the pastel colors IntelliJ uses by default make things harder to read for me personally.

how to open your mod with intelliJ ?

It would be pointless for me to explain every single little thing, just use one of the many tutorials that are out there online.

This person's tutorial series are very good for example, I'd say:
https://www.youtube.com/watch?v=55qUIf3GMss&list=PLKGarocXCE1H9Y21-pxjt5Pt8bW14twa-

how do you decompile and deobfuscate your mod ?
i doesn't find any tutorial on how to do so.

Why would you decompile the mod when it's open-sourced here on GitHub?

thanks