add some spacing to ToC entries to improve deep heading structures

Author: gfldex

assets/sass/style.scss

@@ -494,6 +494,10 @@ table#TOC {
         }
     }
 
+    tr.toc-level-2 td {
+        padding-top: 3pt;
+    }
+
     td.toc-number {
         display: none;
     }

html/css/style.css

@@ -384,6 +384,8 @@ table#TOC {
   table#TOC tr.toc-level-1 td.toc-text {
     position: relative;
     left: 0; }
+  table#TOC tr.toc-level-2 td {
+    padding-top: 3pt; }
   table#TOC td.toc-number {
     display: none; }
   table#TOC code {