add Windows badge

Author: DennisOSRM

index.html

@@ -27,10 +27,12 @@
   </thead>
   <tbody>
     <tr>
-      <td> Project OSRM (master) </td>
+      <td> Project OSRM (master, Linux) </td>
       <td> <img src="https://travis-ci.org/DennisOSRM/Project-OSRM.png?branch=master" alt="Build Status" /></b> </td>
-      <td> Project OSRM (develop) </td>
+      <td> Project OSRM (develop, Linux) </td>
       <td> <img src="https://travis-ci.org/DennisOSRM/Project-OSRM.png?branch=develop" alt="Build Status" /></b> </td>
+      <td> Project OSRM (develop, Windows) </td>
+      <td> <img src="https://ci.appveyor.com/api/projects/status/97g0epxsr6ybmar0/branch/develop" alt="Build Status" /></b> </td>
     </tr>
     <tr>
       <td> <a href="https://scan.coverity.com/projects/183">Coverity Scan</a> (develop) </td>