message: docs: update icon docs
diff: @@ -9,13 +9,15 @@ tag:
  - Interface
  ---
  -The entire theme adds FontClass format icon support in multiple places.
  +The entire theme adds FontClass / Unage format icon support in multiple places.
  You can use iconfont and fontawesome to add icons to your project.
  - For china users, iconfont is recommended
  - For overseas users, fontawesome is recommended
  +Also, png/svg format icon is supported. You can use absolute path or pathname to add icons.
  +
  <!-- more -->
  ## Setting Icons
  