Use button element instead of a for responsive navbar buttons

docs/examples/carousel.html

@@ -279,11 +279,11 @@
         <div class="navbar navbar-inverse">
           <div class="navbar-inner">
             <!-- Responsive Navbar Part 1: Button for triggering responsive navbar (not covered in tutorial). Include responsive CSS to utilize. -->
-            <a class="btn btn-navbar" data-toggle="collapse" data-target=".nav-collapse">
+            <button type="button" class="btn btn-navbar" data-toggle="collapse" data-target=".nav-collapse">
               <span class="icon-bar"></span>
               <span class="icon-bar"></span>
               <span class="icon-bar"></span>
-            </a>
+            </button>
             <a class="brand" href="#">Project name</a>
             <!-- Responsive Navbar Part 2: Place all navbar contents you want collapsed withing .navbar-collapse.collapse. -->
             <div class="nav-collapse collapse">

docs/examples/fluid.html

@@ -47,11 +47,11 @@
     <div class="navbar navbar-inverse navbar-fixed-top">
       <div class="navbar-inner">
         <div class="container-fluid">
-          <a class="btn btn-navbar" data-toggle="collapse" data-target=".nav-collapse">
+          <button type="button" class="btn btn-navbar" data-toggle="collapse" data-target=".nav-collapse">
             <span class="icon-bar"></span>
             <span class="icon-bar"></span>
             <span class="icon-bar"></span>
-          </a>
+          </button>
           <a class="brand" href="#">Project name</a>
           <div class="nav-collapse collapse">
             <p class="navbar-text pull-right">

docs/examples/hero.html

@@ -35,11 +35,11 @@
     <div class="navbar navbar-inverse navbar-fixed-top">
       <div class="navbar-inner">
         <div class="container">
-          <a class="btn btn-navbar" data-toggle="collapse" data-target=".nav-collapse">
+          <button type="button" class="btn btn-navbar" data-toggle="collapse" data-target=".nav-collapse">
             <span class="icon-bar"></span>
             <span class="icon-bar"></span>
             <span class="icon-bar"></span>
-          </a>
+          </button>
           <a class="brand" href="#">Project name</a>
           <div class="nav-collapse collapse">
             <ul class="nav">

docs/examples/starter-template.html

@@ -34,11 +34,11 @@
     <div class="navbar navbar-inverse navbar-fixed-top">
       <div class="navbar-inner">
         <div class="container">
-          <a class="btn btn-navbar" data-toggle="collapse" data-target=".nav-collapse">
+          <button type="button" class="btn btn-navbar" data-toggle="collapse" data-target=".nav-collapse">
             <span class="icon-bar"></span>
             <span class="icon-bar"></span>
             <span class="icon-bar"></span>
-          </a>
+          </button>
           <a class="brand" href="#">Project name</a>
           <div class="nav-collapse collapse">
             <ul class="nav">

docs/examples/sticky-footer-navbar.html

@@ -91,11 +91,11 @@
       <div class="navbar navbar-fixed-top">
         <div class="navbar-inner">
           <div class="container">
-            <a class="btn btn-navbar" data-toggle="collapse" data-target=".nav-collapse">
+            <button type="button" class="btn btn-navbar" data-toggle="collapse" data-target=".nav-collapse">
               <span class="icon-bar"></span>
               <span class="icon-bar"></span>
               <span class="icon-bar"></span>
-            </a>
+            </button>
             <a class="brand" href="#">Project name</a>
             <div class="nav-collapse collapse">
               <ul class="nav">