Introduce integration for mobile documentation

[tallowen]

I added a docs page that would have been helpful for me when integrating pmtiles into a react native app. Two things that required digging for me that I thought would be helpful to write down:

• Versions of maplibre that support pmtiles directly are ~10 weeks old so pointing out that I needed to upgrade would help
• ReactNative does not use the maplibre-gl js library under the hood despite running what looks like a very similar react code which leads to subtle surprises in the APIs. For this project, that's relevant since there is no need to install any special dependencies on mobile.

What it looks like:

[bdon]

The scope of the docs here implicitly concern the code at https://github.com/protomaps - since the MapLibre code lives a totally separate repository and organization (and native doesn't need a plugin, unlike web), maybe there's a better place to put these instructions in the MapLibre org, like at https://maplibre.org/maplibre-native/ios/latest/documentation/maplibre-native-for-ios/pmtiles ?