Tweaked chapter list item styles

- Improves animation smoothness
- Changed animation slideup/down animations to use max-height instead of height
  to better avoid jutter at the end.
- Cleaned spacing to match page items in books listing.

resources/views/chapters/parts/list-item.blade.php

@@ -5,7 +5,7 @@
     <div class="content">
         <h4 class="entity-list-item-name break-text">{{ $chapter->name }}</h4>
         <div class="entity-item-snippet">
-            <p class="text-muted break-text mb-s">{{ $chapter->getExcerpt() }}</p>
+            <p class="text-muted break-text">{{ $chapter->getExcerpt() }}</p>
         </div>
     </div>
 </a>