fix(posts): using feather class

assets/scss/style.scss

@@ -717,13 +717,6 @@ a.footnote-ref {
     border-bottom: 1px solid $theme;
   }
 
-  object {
-    width: 18px;
-    height: 18px;
-    margin-right: .8em;
-    vertical-align: middle;
-  }
-
   .tag {
     margin-right: .5em;