Keyboard shortcuts can now be specified using `about:keyboard`, which is great!
Please add the `Previous Tab` / `Next Tab` command to the list of customisable shortcuts.
There is a related issue tracking the addition of the `Previous Tab` / `Next Tab` commands to the top menu, allowing users to set shortcuts for it on some OSes (e.g. macOS), but this issue is specifically to track the addition of those to `about:keyboard`.