Tabs are inaccessible to keyboard and screen reader users

[schne324]

Refer to the ARIA Authoring Practices Guide: https://www.w3.org/WAI/ARIA/apg/patterns/tabs/examples/tabs-automatic/

• Right Arrow (key === "ArrowRight"):
  • Moves focus to the next tab.
  • If focus is on the last tab, moves focus to the first tab.
  • Activates the newly focused tab.
• Left Arrow (key === "ArrowLeft"):
  • Moves focus to the previous tab.
  • If focus is on the first tab, moves focus to the last tab.
  • Activates the newly focused tab.

Dev Notes

The code changes for this fix should be done in tabs.js within the keydown listener towards the bottom of the file