docs(api_split.pug): add "code" to sidebar entries

Author: hasezoey

docs/api_split.pug

@@ -33,7 +33,7 @@ block content
                 each prop in item.props
                   li
                     a(href='#' + prop.anchorId)
-                      | #{prop.string}
+                      | <code>#{prop.string}</code>
             - else
               div.nav-item-title
                 a(href=item.name.toLowerCase() + '.html')

docs/css/api.css

@@ -32,6 +32,10 @@
   font-size: 0.66em;
 }
 
+.nav-item-sub > li {
+  padding: 2px 0px;
+}
+
 .api-nav ul {
   margin-top: 0.25em;
   padding-left: 1em;