Reorganize menu in "Extending Bazel"

RELNOTES: None.
PiperOrigin-RevId: 178765624
diff --git a/site/_layouts/documentation.html b/site/_layouts/documentation.html
index 8ebd050..690815d 100644
--- a/site/_layouts/documentation.html
+++ b/site/_layouts/documentation.html
@@ -177,24 +177,34 @@
                 <a class="sidebar-nav-heading" data-toggle="collapse"
                     href="#skylark-concepts" aria-expanded="false"
                     aria-controls="skylark-concepts">
-                  Skylark Concepts<span class="caret"></span>
+                  Concepts<span class="caret"></span>
                 </a>
                 <ul class="collapse sidebar-nav sidebar-submenu" id="skylark-concepts">
-                  <li><a href="/versions/{{ site.version }}/skylark/aspects.html">Aspects</a></li>
-                  <li><a href="/versions/{{ site.version }}/skylark/depsets.html">Depsets</a></li>
                   <li><a href="/versions/{{ site.version }}/skylark/macros.html">Macros</a></li>
                   <li><a href="/versions/{{ site.version }}/skylark/rules.html">Rules</a></li>
+                  <li><a href="/versions/{{ site.version }}/skylark/depsets.html">Depsets</a></li>
+                  <li><a href="/versions/{{ site.version }}/skylark/aspects.html">Aspects</a></li>
                   <li><a href="/versions/{{ site.version }}/skylark/repository_rules.html">Repository Rules</a></li>
                 </ul>
               </li>
-              <li><a href="/versions/{{ site.version }}/rule-challenges.html">Writing Rules</a></li>
-              <li><a href="https://skydoc.bazel.build" target="_blank">Documenting Rules</a></li>
-              <li><a href="/versions/{{ site.version }}/skylark/deploying.html">Deploying Rules</a></li>
-              <li><a href="/versions/{{ site.version }}/skylark/performance.html">Optimizing Performance</a></li>
-              <li><a href="/versions/{{ site.version }}/skylark/backward-compatibility.html">Backward Compatibility</a></li>
-              <li><a href="/versions/{{ site.version }}/skylark/skylint.html">Skylark Linter</a></li>
-              <li><a href="/versions/{{ site.version }}/skylark/lib/skylark-overview.html">Modules and Globals</a></li>
-              <li><a href="/versions/{{ site.version }}/skylark/bzl-style.html">BZL File Reference</a></li>
+
+              <li>
+                <a class="sidebar-nav-heading" data-toggle="collapse"
+                    href="#skylark-practices" aria-expanded="false"
+                    aria-controls="skylark-practices">
+                  Best Practices<span class="caret"></span>
+                </a>
+                <ul class="collapse sidebar-nav sidebar-submenu" id="skylark-practices">
+                  <li><a href="/versions/{{ site.version }}/skylark/bzl-style.html">Readability Guidelines</a></li>
+                  <li><a href="/versions/{{ site.version }}/skylark/backward-compatibility.html">Backward Compatibility</a></li>
+                  <li><a href="https://skydoc.bazel.build" target="_blank">Documenting Rules</a></li>
+                  <li><a href="/versions/{{ site.version }}/skylark/skylint.html">Skylark Linter</a></li>
+                  <li><a href="/versions/{{ site.version }}/skylark/performance.html">Optimizing Performance</a></li>
+                  <li><a href="/versions/{{ site.version }}/skylark/deploying.html">Deploying Rules</a></li>
+                </ul>
+              </li>
+
+              <li><a href="/versions/{{ site.version }}/skylark/lib/skylark-overview.html">API Reference</a></li>
               <li><a href="/versions/{{ site.version }}/skylark/language.html">Skylark Language Reference</a></li>
             </ul>
           </nav>