Sidebar tree css selector fix #126 (#131)

static/assets/css/layouts/single.css

@@ -64,6 +64,7 @@ body {
 }
 
 .toc ul {
+  list-style: none;
   padding-left: 0.5rem;
   width: 100%;
 }

static/assets/css/navigators/sidebar.css

@@ -55,7 +55,7 @@
 }
 
 .tree,
-ul {
+.tree ul {
   margin: 0;
   padding: 0;
   list-style: none;