docs: inject sidebar active link scroll into view script

Author: btea

doc/template.html

@@ -64,7 +64,7 @@ <h1>Node.js __VERSION__ documentation</h1>
                 <span class="picker-arrow"></span>
                 Options
               </a>
-        
+
               <div class="picker" tabindex="-1">
                 <ul id="options-picker">
                   <li>
@@ -73,7 +73,7 @@ <h1>Node.js __VERSION__ documentation</h1>
                   <li>
                     <a href="__FILENAME__.json">View as JSON</a>
                   </li>
-                  __EDIT_ON_GITHUB__    
+                  __EDIT_ON_GITHUB__
                 </ul>
               </div>
             </li>
@@ -90,5 +90,14 @@ <h1>Node.js __VERSION__ documentation</h1>
       </div>
     </div>
   </div>
+  <script>
+    const activeLInk = document.querySelector('.interior ul .active');
+    if (activeLInk) {
+      activeLInk.scrollIntoView({
+        behavior: 'smooth',
+        block: 'center'
+      });
+    }
+  </script>
 </body>
 </html>