There is nothing interesting nor Gentoo-specific below.
I use VSCode occasionally, but I tend to have many projects open at once, so I use Neovim+LazyVim.
For LazyVim:
/etc/portage/package.accept_keywords/vim
dev-vcs/lazygit ~amd64
For neovim:
/etc/portage/package.use/vim
dev-lua/lpeg lua_targets_lua5-4