Fix HTML5 validation errors

docs/components.html

@@ -152,7 +152,7 @@ title: Components · Ratchet
           </button>
           <button class="btn pull-right">
             Right
-          </a>
+          </button>
           <div class="segmented-control">
             <a class="control-item active">One</a>
             <a class="control-item">Two</a>
@@ -165,7 +165,7 @@ title: Components &middot; Ratchet
 <header class="bar bar-nav">
   <button class="btn pull-left">
     Left
-  </a>
+  </button>
   <button class="btn pull-right">
     Right
   </button>
@@ -750,7 +750,7 @@ title: Components &middot; Ratchet
       <button class="btn btn-negative">Button</button>
       <button class="btn btn-link">Button</button>
 
-      <button class="btn btn-outlined">Button</a>
+      <button class="btn btn-outlined">Button</button>
       <button class="btn btn-primary btn-outlined">Button</button>
       <button class="btn btn-positive btn-outlined">Button</button>
       <button class="btn btn-negative btn-outlined">Button</button>
@@ -763,7 +763,7 @@ title: Components &middot; Ratchet
 <button class="btn btn-negative">Button</button>
 <button class="btn btn-link">Button</button>
 
-<button class="btn btn-outlined">Button</a>
+<button class="btn btn-outlined">Button</button>
 <button class="btn btn-primary btn-outlined">Button</button>
 <button class="btn btn-positive btn-outlined">Button</button>
 <button class="btn btn-negative btn-outlined">Button</button>