🚀 Feature

Highlight the current section in the onPageNav ToC that the reader has scrolled to, either by a background color or bold or adding a customizable CSS class.

Basically, the way scrollspy works in Bootstrap.

Have you read the Contributing Guidelines on issues?

Yup.

Motivation

If a page has a long ToC (i.e. most of our tutorial pages have 9-10 steps), it would make it a lot easier for the reader to know where they are if the current step they have scrolled to is somehow highlighted in the ToC.

Pitch

This could be a universal feature in Docusaurus 2.0. I think it would make Docusaurus sites look even more professional.