Migrating the base API URL for the react native example to an .env file.

examples/bot-ready-signalling/client/react-native/README.md

@@ -34,6 +34,10 @@ npm i
 
 # Before a native app can be compiled, the native source code must be generated.
 npx expo prebuild
+
+# Configure the environment variable to connect to the local server
+cp env.example .env
+# edit .env and add your local ip address, for example: http://192.168.1.16:7860
 ```
 
 #### Running on Android
@@ -53,4 +57,4 @@ npm run ios
 ```
 
 #### Connect to the server
-Use the http://localhost:5173 in your app.
+Use the http://localhost:5173 in your app.