[Enhancement]: TOC lacks active section highlighting and auto-scroll

[Pranav-IIITM]

Description

On the tutorial pages for example, The Basic Tools of the Deep Life Sciences, the right-hand sidebar containing the Table of Contents (TOC) for the current page has two usability issues:

1. No Active Section Highlighting (Scrollspy): As the user scrolls through the main document, the TOC does not highlight or indicate which section is currently being read.
2. No Auto-scrolling: The TOC does not scroll automatically to keep the active section in view or as the user progresses deep into the document.

Enhancement

• Active state: The section currently in the viewport on the main page should be highlighted in the right TOC ( a scrollspy feature).
• Auto-scroll: The TOC should ideally scroll to ensure the currently active section remains visible within the sidebar.

Expected Outcome

It will look something like this (TOC on the right):

toc.highlighting.active.sections.mp4

Why it matters

Adding this would:

• Make it easier for users to navigate long tutorials without losing their place.
• Improve the overall usability and polish of the tutorials, which are often a new user's first hands-on introduction to DeepChem.

[Pranav-IIITM]

@rbharath Would love your Insights !!
Also I would like to work on it if maintainers likes this Enhancement