Table of Contents don't highlight pages without `*.html` suffix

[songpola]

When clicking the Next Chapter button (> on the right) or any links, the target pages don't have *.html suffix
(e.g. https://flake.parts/getting-started).
But links from the TOC have the target pages with *.html suffix (e.g. https://flake.parts/getting-started.html).
I'm not sure, but this might cause the TOC to not highlight the current pages if that page doesn't have *.html suffix.

Example

https://flake.parts/getting-started.html (TOC hightlighted current page)

https://flake.parts/getting-started (TOC did not hightlight current page)