add readme

README.md

@@ -4,4 +4,22 @@ A flutter package for showing a country code selector.
 
 ## Usage
 
+Just put the component in your application setting the onChanged callback.
 
+ ```dart
+ ......
+ @override
+  Widget build(BuildContext context) => new Scaffold(
+      body: new Center(
+        child: new CountryCodePicker(
+          onChanged: print,
+        ),
+      ));
+.....
+ ```
+
+ It's also possible to select the initial selection using the country code.
+
+## Known issues
+
+- On iOS the icons are not showned

lib/country_code_picker.dart

@@ -41,8 +41,13 @@ class _CountryCodePickerState extends State<CountryCodePicker> {
 
   @override
   initState() {
-    selectedItem = elements.firstWhere((e) => e.code == widget.initialSelection,
+    if (widget.initialSelection != null) {
+      selectedItem = elements.firstWhere(
+          (e) => e.code.toUpperCase() == widget.initialSelection.toUpperCase(),
           orElse: () => elements[0]);
+    }else{
+      selectedItem = elements[0];
+    }
     super.initState();
   }