Prepare mods collection

_config.yml

@@ -30,9 +30,14 @@ google_analytics: # leave it blank if not wish
 fb_appid:
 
 # Collection setting
+collections_dir: collections
 collections:
   posts:
     output: true
+    permalink: /posts/:title
+  mods:
+    output: true
+    permalink: /mods/:title
 
 # Markdown settings
 markdown: kramdown