=== Description
Minor visual changes to the table of contents and main menu.
Current: https://en.wikipedia.org/wiki/Finland?useskin=vector-2022&tableofcontents=true
Updated: https://di-toc-with-menu-above.web.app/Tuna
[] Remove border from ToC and main menu
[] Reduce font-size of "Contents" heading to 16px
[] Replace ToC section toggle icons with chevrons
{F35030662}
[] add `transition: 100ms` to section toggle icons, this transition should take into account the `prefers-reduced-motion` media query
[] Adjust spacing around and between ToC elements
{F35030584 width=600}
=== Developer notes
Based off conversation with @alexhollender_WMF in today's web planning meeting, the new icon doesn't have to be added to OOUI, and we can add the svg directly to Vector to be used. The other visual changes seem relatively straightforward