[ Suggestion ] - treat `lib`, `src` folders like `index.js`

[benpptung]

Just an idea.
Now, smart-tab will highlight parent folder name if the filename name is index.js.
I am thinking, if the folder name is lib or src, maybe, smart-tab can highlight the parent folder's parent folder, because lib and src sometimes are too common.

[MoOx]

PR welcome :)