Update README.md (#127)

* Update README.md

Add an React native Development Environment Installation Guide (that guides user through lacking steps in the Android installation) such as setting JAVA_HOME directory for your profile.

* Update example/README.md

Co-authored-by: Uddish Verma <[email protected]>

---------

Co-authored-by: Uddish Verma <[email protected]>

Author: mleszkiewicz

example/README.md

@@ -21,7 +21,11 @@ sh scripts/generateEnv.sh
 This command will create a .env file <b>inside the example directory</b>.
 Fill in the required App ID in the .env file. Other variables are optional.
 
+## Before you run the app
+ 
+Please set up your React Native Development Environment for Android as described in the guide below (if you didn't do it before):
 
+[Android enviroment setup](https://reactnative.dev/docs/environment-setup?package-manager=yarn&guide=native&platform=android)
 
 ## Running the app
 
@@ -46,4 +50,4 @@ pod install
 
 2. For issues related to android, try opening and running the example app from the android studio.
 
-3. For general iOS build errors, opening and running the example app from XCode also helps.
+3. For general iOS build errors, opening and running the example app from XCode also helps.