Update setup.rst for V6.0

Creating the correct command and fixing the installation problem of version 6.0

Author: BahmanMD

setup.rst

@@ -54,10 +54,10 @@ application:
 .. code-block:: terminal
 
     # run this if you are building a traditional web application
-    $ symfony new my_project_name --version="5.4.x@dev" --full
+    $ symfony new my_project_name --version="6.0.x@dev" --full
 
     # run this if you are building a microservice, console application or API
-    $ symfony new my_project_name --version="5.4.x@dev"
+    $ symfony new my_project_name --version="6.0.x@dev"
 
 The only difference between these two commands is the number of packages
 installed by default. The ``--full`` option installs all the packages that you