Use --dev in readme

ruudk · ruudk · commit 841739f4229e · 2024-08-26T09:49:46.000+02:00
diff --git a/README.md b/README.md
@@ -11,7 +11,7 @@
 ## Installation
 
 ```command
-$ composer require ticketswap/phpstan-error-formatter
+$ composer require --dev ticketswap/phpstan-error-formatter
 ```
 
 ## Usage
