Merge branch '6.0' into 6.1

* 6.0:
  Add return types in docs to avoid generating more legacy code
  Update configuration.rst to aviod misunderstanding

Author: javiereguiluz

configuration.rst

@@ -764,7 +764,7 @@ Configuring Environment Variables in Production
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 In production, the ``.env`` files are also parsed and loaded on each request. So
-the easiest way to define env vars is by deploying a ``.env.local`` file to your
+the easiest way to define env vars is by creating a ``.env.local`` file on your
 production server(s) with your production values.
 
 To improve performance, you can optionally run the ``dump-env`` command (available

controller/argument_value_resolver.rst

@@ -195,7 +195,7 @@ retrieved from the token storage::
             $this->security = $security;
         }
 
-        public function supports(Request $request, ArgumentMetadata $argument)
+        public function supports(Request $request, ArgumentMetadata $argument): bool
         {
             if (User::class !== $argument->getType()) {
                 return false;
@@ -204,7 +204,7 @@ retrieved from the token storage::
             return $this->security->getUser() instanceof User;
         }
 
-        public function resolve(Request $request, ArgumentMetadata $argument)
+        public function resolve(Request $request, ArgumentMetadata $argument): iterable
         {
             yield $this->security->getUser();
         }