[enh] landing page updates

searx/templates/index.html

@@ -1,8 +1,10 @@
 {% extends "base.html" %}
 {% block content %}
+<div class="center">
     <h1>searx</h1>
     <form method="post" action="">
-    <input type="text" name="q" />
+        <input type="text" name="q" tabindex="1" />
         <input type="submit" value="search" />
     </form>
+</div>
 {% endblock %}