Added example.

example/example.dart

@@ -0,0 +1,14 @@
+import 'dart:io';
+
+import 'package:dcat/dcat.dart';
+
+// Usage: dart example.dart file...
+Future<void> main(List<String> arguments) async {
+  // Display the file(s) with line numbers to the standard output
+  final result = await cat(arguments, stdout, showLineNumbers: true);
+  if (result.isFailure) {
+    for (final error in result.errors) {
+      print("Error with '${error.path}': ${error.message}");
+    }
+  }
+}