docs/website: add a space between attributes

Error highlighted by the W3 HTML validator:

Error: No space between attributes.
At line 71, column 64
e="width:100%;"href="/download

Signed-off-by: Vicente Olivert Riera <Vincent.Riera@imgtec.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

docs/website/index.html

@@ -19,7 +19,7 @@
           <a class="btn btn-primary btn-lg" style="width:100%;" href="/about.html"><span class="glyphicon glyphicon-info-sign"></span> Learn more »</a>
           </div>
           <div class="col-sm-6" style="margin-top:1em; padding-left:0px;">
-          <a class="btn btn-primary btn-lg" style="width:100%;"href="/download.html"><span class="glyphicon glyphicon-cloud-download"></span> Download »</a>
+          <a class="btn btn-primary btn-lg" style="width:100%;" href="/download.html"><span class="glyphicon glyphicon-cloud-download"></span> Download »</a>
           </div>
         </div>
       </div>