Task: Add TextFormatter function to format the string with args

example/text_formatter_example.dart

@@ -0,0 +1,14 @@
+import 'package:configurable/text_formatter.dart';
+
+void main(List<String> args) {
+  var text1 = 'Hello, {0}, then do this it by {1}!';
+  var text2 = 'Hello, {firstName}, then do this it by {lastName}!';
+  var result1 = TextFormatter(text1).format(['Sambo', 'Chea']);
+  var result2 = TextFormatter(text2).decorate({
+    'firstName': 'Sambo',
+    'lastName': 'Chea',
+  });
+
+  print('Result 1 => $result1');
+  print('Result 2 => $result2');
+}