Update README.md

Author: scottrhoyt

README.md

@@ -22,7 +22,7 @@ The algorithms are documented in
 * GeographicLib: https://geographiclib.sourceforge.io
 * C implementation: https://github.com/geographiclib/geographiclib-c
 
-## WIP
+## 🚧 WIP 🚧
 
 *The public API of this library is a WIP. It aims to be faithful to map directly to the underlying C libraries while being more idiomatically Swift. Be aware of potential breaking changes to the API until 1.0.0 and pin to specific minor versions if needed.*