The 'T' key will show/hide the most recent sidebar tab.
Pressing 'Shift+T' will switch to the next sidebar tab, possibly
wrapping around to the first tab.
If the Itinerary tab is hidden, it will be skipped.
Based on leaflet-sidebar-v2 fork of sidebar-v2:
- Simpler because Leaflet-only
- autopan option
- seems more active with two contributers
Customization for brouter-web in own fork (WIP):
- hidden bar when collapsed
- flat design to match header/footer
- flexbox layout beside map instead of media breakpoints