Change app to bin .

Change `app` to `bin` to be consistent with others examples.

Author: ismail1432

console/input.rst

@@ -183,7 +183,7 @@ separation at all (e.g. ``-i 5`` or ``-i5``).
 
     While it is possible to separate an option from its value with a white space,
     using this form leads to an ambiguity should the option appear before the
-    command name. For example, ``php app/console --iterations 5 app:greet Fabien``
+    command name. For example, ``php bin/console --iterations 5 app:greet Fabien``
     is ambiguous; Symfony would interpret ``5`` as the command name. To avoid
     this situation, always place options after the command name, or avoid using
     a space to separate the option name from its value.