Add `item-meta-info-reading-time` CSS class

internal/template/templates/common/item_meta.html

@@ -8,7 +8,7 @@
             <time datetime="{{ isodate .entry.Date }}" title="{{ isodate .entry.Date }}">{{ elapsed .user.Timezone .entry.Date }}</time>
         </li>
         {{ if and .user.ShowReadingTime (gt .entry.ReadingTime 0) }}
-        <li>
+        <li class="item-meta-info-reading-time">
             <span>
             {{ plural "entry.estimated_reading_time" .entry.ReadingTime .entry.ReadingTime }}
             </span>