Add a QA about fixing map data

FAQ.md

@@ -10,6 +10,11 @@ This is a collection of answers to the most frequently asked questions about Lea
 
 ## Data Providers
 
+#### The map is wrong in my neighborhood, could you fix it?
+
+Nope, but you can. The map you see on Leaflet examples is based on [OpenStreetMap], a free editable map of the world.
+Signing up and editing the map there is easy, and the changes will be reflected on the map in a few minutes.
+
 #### What map tiles can I use with Leaflet? Is it limited to OpenStreetMap?
 
 Leaflet is provider-agnostic, meaning you can use any map provider as long as you conform to its terms of use.