Make steps of download look like intermediary steps of step 1

This does not apply to DVD and VM which don't have numbered steps.

wiki/src/install/inc/steps/download_2.inline.html

@@ -9,11 +9,11 @@
     <h2>Direct download</h2>
 
     <div class="supported-browser no-js">
-      <h3><span class="step-number">1.</span>Download Tails</h3>
+      <h3><span class="step-number"><span class="debian windows linux mac-usb mac-dvd upgrade-tails">1.</span>1.</span>Download Tails</h3>
       <a id="download-iso" class="btn btn-primary indent">Download Tails 3.1 ISO image (1.2 GB)</a>
 
       <div id="step-verify-direct">
-        <h3><span class="step-number">2.</span>Verify your download using your browser</h3>
+        <h3><span class="step-number"><span class="debian windows linux mac-usb mac-dvd upgrade-tails">1.</span>2.</span>Verify your download using your browser</h3>
         <div class="caution indent">
           <p><b>For your security, always verify your download!</b><br/>
                 Our browser extension makes it quick and easy.</p>
@@ -73,7 +73,7 @@
       </div>
 
       <div id="step-continue-direct">
-        <h3><span class="step-number">3.</span>Continue installing</h3>
+        <h3><span class="step-number"><span class="debian windows linux mac-usb mac-dvd upgrade-tails">1.</span>3.</span>Continue installing</h3>
       </div>
       <div id="continue-link-direct" class="indent">
         <div id="skip-download-direct">
@@ -145,16 +145,16 @@
     <h2>BitTorrent download</h2>
     <a>What is BitTorrent?</a>
 
-    <h3><span class="step-number">1.</span>Download Tails (Torrent file)</h3>
+    <h3><span class="step-number"><span class="debian windows linux mac-usb mac-dvd upgrade-tails">1.</span>1.</span>Download Tails (Torrent file)</h3>
     <a id="download-torrent" class="btn btn-primary indent">Download Tails 3.1 Torrent file</a>
 
     <div id="step-verify-bittorrent">
-      <h3><span class="step-number">2.</span>Verify your download using BitTorrent</h3>
+      <h3><span class="step-number"><span class="debian windows linux mac-usb mac-dvd upgrade-tails">1.</span>2.</span>Verify your download using BitTorrent</h3>
       <p class="indent">Your BitTorrent client will automatically verify your download when it is complete.</p>
     </div>
 
     <div id="step-continue-bittorrent">
-      <h3><span class="step-number">3.</span>Continue installing</h3>
+      <h3><span class="step-number"><span class="debian windows linux mac-usb mac-dvd upgrade-tails">1.</span>3.</span>Continue installing</h3>
     </div>
     <div id="continue-link-bittorrent" class="indent">
       <div id="skip-download-bittorrent">