Open active link in navigation (#43)

* Add class to current active link and open parents

* Style for active-link

Author: toshimaru

src/_sass/railsdoc.scss

@@ -102,6 +102,11 @@ code {
     }
   }
 
+  .active-link {
+    font-weight: bold;
+    text-decoration: underline;
+  }
+
   .icon {
     cursor: pointer;
     background: url("/assets/image/arrow-right.svg");

src/assets/js/app.js

@@ -8,4 +8,8 @@ $(() => {
 
   anchors.options.visible = 'always';
   anchors.add();
+
+  $(`.sidebar-content a[href='${window.location.pathname}']`)
+    .attr("class", "active-link")
+    .parents('ul').show();
 });