Add example, fix readme
diff --git a/README.md b/README.md
index 4c8f313..fc82c25 100644
--- a/README.md
+++ b/README.md
@@ -14,9 +14,18 @@
 the most common file name extensions and magic bytes registered.
 
 ```dart
-print(lookupMimeType('test.html'));  // Will print text/html
-print(lookupMimeType('test', [0xFF, 0xD8]));  // Will print image/jpeg
-print(lookupMimeType('test.html', [0xFF, 0xD8]));  // Will print image/jpeg
+import 'package:mime/mime.dart';
+
+void main() {
+  print(lookupMimeType('test.html'));
+  // text/html
+
+  print(lookupMimeType('test', headerBytes: [0xFF, 0xD8]));
+  // image/jpeg
+
+  print(lookupMimeType('test.html', headerBytes: [0xFF, 0xD8]));
+  // image/jpeg
+}
 ```
 
 You can build you own resolver by creating an instance of
diff --git a/example/example.dart b/example/example.dart
new file mode 100644
index 0000000..af14cb0
--- /dev/null
+++ b/example/example.dart
@@ -0,0 +1,12 @@
+import 'package:mime/mime.dart';
+
+void main() {
+  print(lookupMimeType('test.html'));
+  // text/html
+
+  print(lookupMimeType('test', headerBytes: [0xFF, 0xD8]));
+  // image/jpeg
+
+  print(lookupMimeType('test.html', headerBytes: [0xFF, 0xD8]));
+  // image/jpeg
+}