Update README.md

clarkeash · web-flow · commit 979af675db43 · 2017-09-10T16:22:20.000+02:00
diff --git a/README.md b/README.md
@@ -20,6 +20,12 @@ Validates 2 & 3 character country codes.
   </a>
 </p>
 
+## Installation
+
+```bash
+composer require laravel-validation-rules/country-codes
+```
+
 ## Usage
 
 Validate a 2 character country code.
