Adding subdir support

lib/content.go

@@ -35,6 +35,14 @@ func ListContent(dir string) ([]Content, error) {
   }
 
   for _, e := range entries {
+    if e.IsDir() {
+      subres, err := ListContent(path.Join(dir, e.Name()))
+      if err != nil {
+        return res, err
+      }
+      res = append(res, subres...)
+    }
+
     if(!strings.HasSuffix(e.Name(), ".json")) {
       continue
     }