Change ToC title on page scroll.

[HarshKapadia2]

• Change the title of the Table of Contents (ToC) from 'Table of Contents' to the title of the document.
• Conditions to be met to make this change
  • When the ToC is on the left/right.
  • When the header is not visible.
• Things to keep in mind
  • Handling of overflow of extra-long titles.
  • Detection of whether the ToC is on the left/right or not.
    • It doesn't make sense to make the change if the ToC is in the normal flow of the document.
  • Changing the ToC title back to 'Table of Contents' from the document title when a left/right aligned ToC goes to its normal flow in the document.

Current behaviour (top left)

Expected behaviour (top left)

No change to ToC title if doc title is visible

No change to ToC title if ToC is in the normal flow of the document