Updated DirectXTex (markdown)

DirectXTex.md

@@ -188,7 +188,7 @@ In your application's solution, right-click on the Solution and use "Add \ Exist
  </tr>
  <tr>
   <td>DirectXTex_GDK_2019</td>
-  <td>Windows 10 and Xbox games building with VS 2019 using the [Microsoft GDK](https://github.com/microsoft/gdk).</td>
+  <td>Windows 10 and Xbox games building with VS 2019 using the <a href="https://github.com/microsoft/gdk">Microsoft GDK</a>.</td>
  </tr>
 </table>
 
@@ -209,7 +209,7 @@ In your application's solution, right-click on the Solution and use "Add \ Exist
  </tr>
  <tr>
   <td>DirectXTex_GDK_2017</td>
-  <td>Windows 10 and Xbox games building with VS 2017 using the [Microsoft GDK](https://github.com/microsoft/gdk).</td>
+  <td>Windows 10 and Xbox games building with VS 2017 using the <a href="https://github.com/microsoft/gdk">Microsoft GDK</a>.</td>
  </tr>
  <tr>
   <td>DirectXTex_XboxOneXDK_2017</td>