Add a new toggle button for showing and hiding a nearby articles layer in maps. This doesn't have to be connected to any logic yet.
- Should be hidden behind a feature flag until the MVP implementation is complete.
- Should send some kind of metrics instrumentation.
- Metrics can be retrieved using API request data in combination with a special user agent
Dev note: For the first proof of concept/demo it's okay to reuse the existing layer selector (see screenshot below) (if it turns out to be generated by Kartographer rather than by custom JS on Wikivoyage, also see the notes below) or add a new button at the bottom, whatever is easier to implement. Final UI/UX design will l be done later.
