Adding a fake 2.8 StimulusBundle recipe so that you always at least get the bundle installed

Even if you can't execute the 2.9 recipe due to the "conflicts" inside.

Author: weaverryan

symfony/stimulus-bundle/2.8/manifest.json

@@ -0,0 +1,6 @@
+{
+    "bundles": {
+        "Symfony\\UX\\StimulusBundle\\StimulusBundle": ["all"]
+    },
+    "aliases": ["stimulus", "stimulus-bundle"]
+}