Make in-stream moderation a default plugin

plugins.default.json

@@ -20,6 +20,7 @@
     "talk-plugin-sort-most-replied",
     "talk-plugin-author-menu",
     "talk-plugin-member-since",
-    "talk-plugin-ignore-user"
+    "talk-plugin-ignore-user",
+    "talk-plugin-moderation-actions"
   ]
 }