Upload app styles sheet

Growth_monitoring-FRONTEND/Styles/AppStyles.js

+import { StyleSheet } from 'react-native';
+
+const AppStyles = StyleSheet.create({
+  container: {
+    flex: 1,
+    alignItems: 'center',
+    justifyContent: 'center',
+  },
+  appName: {
+    fontSize: 20,
+    fontWeight: 'bold',
+    fontFamily: 'sans-serif-medium',
+    color: '#fff8dc' // You can change this color to whatever you want
+  }
+});
+
+export default AppStyles;