Fix several erroneous links in docs.

Related to #17314.

docs/examples/index.md

@@ -34,7 +34,7 @@ Examples that focus on implementing uses of built-in components provided by Boot
     <p>Build around the jumbotron with a navbar and some basic grid columns.</p>
   </div>
   <div class="col-xs-6 col-md-4">
-    <a href="{{ site.baseurl }}/examples/jumbotron-narrow/">
+    <a href="{{ site.baseurl }}/examples/narrow-jumbotron/">
       <img class="img-thumbnail" src="{{ site.baseurl }}/examples/screenshots/jumbotron-narrow.jpg" alt="">
     </a>
     <h4>Narrow jumbotron</h4>

docs/examples/navbar/index.html

@@ -42,7 +42,7 @@
         <h1>Navbar example</h1>
         <p>This example is a quick exercise to illustrate how the default navbar works. It's placed within a <code>.container</code> to limit its width and will scroll with the rest of the page's content.</p>
         <p>
-          <a class="btn btn-lg btn-primary" href="../../components/#navbar" role="button">View navbar docs &raquo;</a>
+          <a class="btn btn-lg btn-primary" href="../../components/navbar" role="button">View navbar docs &raquo;</a>
         </p>
       </div>
 

docs/examples/offcanvas/index.html

@@ -36,8 +36,8 @@
         <div id="navbar" class="collapse navbar-collapse">
           <ul class="nav navbar-nav">
             <li class="active"><a href="#">Home</a></li>
-            <li><a href="#about">About</a></li>
-            <li><a href="#contact">Contact</a></li>
+            <li><a href="#">About</a></li>
+            <li><a href="#">Contact</a></li>
           </ul>
         </div><!-- /.nav-collapse -->
       </div><!-- /.container -->

docs/examples/sticky-footer-navbar/index.html

@@ -38,8 +38,8 @@
         <div id="navbar" class="collapse navbar-collapse">
           <ul class="nav navbar-nav">
             <li class="active"><a href="#">Home</a></li>
-            <li><a href="#about">About</a></li>
-            <li><a href="#contact">Contact</a></li>
+            <li><a href="#">About</a></li>
+            <li><a href="#">Contact</a></li>
             <li class="dropdown">
               <a href="#" class="dropdown-toggle" data-toggle="dropdown" role="button" aria-expanded="false">Dropdown</a>
               <div class="dropdown-menu">