defect: Table of Contents links covered by jump links

[mattleff]

When viewing the Glossary (​https://wordpress.org/support/article/glossary/
) and possibly other pages, the Table of Contents sidebar links next to the jump to Top links are un-clickable. The jump to Top links are above (z-index) the sidebar links. This can be fixed with either:

.table-of-contents {
    ...
    z-index: 2;
}

Or removing:

p.toc-jump {
    z-index: 1;
}

[dd32]

In 9859:

Support: Ensure that the TOC jump links don't block clicking the TOC itself.

Props mattleff.
Fixes #5206.