Fix option name: use ignored_namespaces instead of ignore_namespaces

Author: OskarStark

.doctor-rst.yaml

@@ -25,7 +25,7 @@ rules:
         namespace_mapping:
             'src/': 'App\'
             'tests/': 'App\Tests\'
-        ignore_namespaces:
+        ignored_namespaces:
             - 'Acme\'
         ignored_paths:
             - '/^config\//'