refactor: base of JetBrains

[jef]

Description

From sainnhe/everforest#28

Move from Nord base to Gruvbox base to be consistent with theme.

Possible solution

From @sainnhe:

...This color scheme is designed to be warm and soft, its main colors are red, orange, yellow and green. The current syntax highlighting is based on gruvbox-material which is inspired by gruvbox, its highlighting logic exactly coincides with the design. So I think maybe you can consider changing the highlight logic part of jetbrains to gruvbox based.

https://plugins.jetbrains.com/plugin/12310-gruvbox-theme