[Router] Add recipe for 5.1 router default URI config

symfony/routing/5.1/config/packages/prod

@@ -0,0 +1 @@
+../../../4.2/config/packages/prod/

symfony/routing/5.1/config/packages/routing.yaml

@@ -0,0 +1,7 @@
+framework:
+    router:
+        utf8: true
+
+        # Configure how to generate URLs in non-HTTP contexts, such as CLI commands.
+        # See https://symfony.com/doc/current/routing.html#generating-urls-in-commands
+        #default_uri: http://localhost

symfony/routing/5.1/config/routes.yaml

@@ -0,0 +1 @@
+../../4.2/config/routes.yaml

symfony/routing/5.1/manifest.json

@@ -0,0 +1 @@
+../4.2/manifest.json