add a warning about lat/lng order

docs/api_quick.md

@@ -1,6 +1,5 @@
 # API Quick Reference
 
-
 ```{attention}
 Function names changed significantly with `h3-py` `v4.0` to align with the C library: https://h3geo.org/docs/library/migration-3.x/functions
 ```
@@ -120,6 +119,11 @@ The objects and functions also compatible with the popular [``__geo_interface__`
 
 See the [polygon tutorial](./polygon_tutorial.ipynb) for a walkthrough.
 
+```{warning}
+As with other `h3-py` functions, the polygon interface expects coordinate pairs in **lat/lng** order.
+Note that this is reversed from ``__geo_interface__`` objects, which are given in **lng/lat** order.
+```
+
 ### Polygon objects
 
 ```{eval-rst}