fix: ToC tap target size (Lighthouse)

wowchemy/assets/scss/wowchemy/layouts/_book.scss

@@ -243,7 +243,8 @@ ul.toc-top {
 #TableOfContents li a,
 .toc-top li a {
   display: block;
-  padding: 0.125rem 1.5rem;
+  padding: 0 1.5rem;  // Override default padding
+  margin-bottom: 8px;  // Lighthouse: tap targets must be at least 8px apart
   color: rgba(0, 0, 0, 0.65);
   font-size: 0.7rem;
 }