[Dotenv] Advise using the Composer --dev option

ogizanagi · web-flow · commit 2e13c8bda3c9 · 2018-09-25T16:38:10.000+02:00
diff --git a/components/dotenv.rst b/components/dotenv.rst
@@ -16,7 +16,7 @@ Installation
 
 .. code-block:: terminal
 
-    $ composer require symfony/dotenv
+    $ composer require --dev symfony/dotenv
 
 Alternatively, you can clone the `<https://github.com/symfony/dotenv>`_ repository.
 
