Improve documentation for dump command (#426)

* Improve documentation for dump command

* Fix whitespace

Author: sprain

Command/DumpCommand.php

@@ -56,7 +56,7 @@ protected function configure(): void
                 'target',
                 null,
                 InputOption::VALUE_OPTIONAL,
-                'Override the target directory to dump routes in.'
+                'Override the target file to dump routes in.'
             )
             ->addOption(
                 'locale',

Resources/doc/commands.rst

@@ -43,8 +43,10 @@ Or inside assetic, do
 .. tip::
 
     If you are using JMSI18nRoutingBundle, you need to run the command with the
-    ``--locale`` parameter once for each locale you use and adjust your include
-    paths accordingly.
+    ``--locale`` parameter and a custom ``--target`` once for each locale you use.
+    Then adjust your include path accordingly. Note that you can only load the dump
+    of one locale at once in your html as each following dump would overwrite the
+    data of the previous one.
 
 fos:js-routing:debug
 --------------------