[accessibility] Potential requirements of tablists

[Malvoz]

Looking at the WAI-ARIA Authoring Practices' documentation on tabs, there seem to be quite a few requirements for accessible tabs, such as: conveying the relationship between a tab and a tabpanel (sidebar-panes should be tabpanel), and keyboard interactions.

They also provide an example implementation of a fully accessible tablist component, which might be helpful, here:
https://www.w3.org/TR/wai-aria-practices-1.1/examples/tabs/tabs-2/tabs.html

Other potentially helpful resources:

• Leaflet Guideline: Test your maps
• Leaflet Plugin Authoring Guide: Content Accessibility