suggestion: specify the syntax plugins used for language highlighting

[jinh0]

Taking inspiration from Nord https://github.com/arcticicestudio/nord-vim/blob/develop/colors/nord.vim:

Think we should also add these comments before every plugin-specific highlight groups

" > HerringtonDarkholme/yats.vim

especially for JavaScript and Typescript since they require these excellent syntax plugins.

I also think we should add this information into the README.md. Oftentimes, after installing a new Vim color scheme and getting wrong colors, I just give up, when I could have just installed the right plugin that the color scheme wants you to use.