include geoflatbush reference in readme

README.md

@@ -1,6 +1,6 @@
 # Flatbush Dart
 
-A fast static spatial index for 2D points and rectangles in Dart, ported from the [excellent JavaScript implementation](https://github.com/mourner/flatbush/tree/main) by [Volodymyr Agafonkin](https://github.com/mourner).
+A fast static spatial index for 2D points and rectangles in Dart, ported from the [excellent JavaScript implementation](https://github.com/mourner/flatbush/tree/main) by [Volodymyr Agafonkin](https://github.com/mourner), and includes [the extension for geographic queries](https://github.com/mourner/geoflatbush).
 
 
 ## Usage
@@ -10,7 +10,7 @@ A fast static spatial index for 2D points and rectangles in Dart, ported from th
 final index = Flatbush.double64(1000);
 
 // fill it with 1000 rectangles
-for (final p of items) {
+for (final p in items) {
     index.add(
       minX: p.minX,
       minY: p.minY,