Option to have separator

[louim]

It would be nice to have an option to pass an element that would be referenced in the table of contents as a separator.

[gajus]

Please provide an example.

[louim]

I think the best case /example would be something like this

<h2>something</h2>
<h2 class="separator">something</h2>
<h2>something</h2>

Separator class would be passed to the configuration, and would result in the table of content element having the same class so I can assign it different styling. The element in the table of content would also be non clickable.

I realized after opening the issue that I could probably attain the same result by creating a custom link function as shown in the doc, but I think it would be useful working out of the box.