title: Add attribute to root element in schema XML
body: <p>I have a root element named "Project". This root contains type named "Layer", but I don't know how to define attributes to the root (Project) element.</p>
  
  <p>This attribute which want add to root:</p>
  
  <pre><code> &lt;attribute name="name" type="string" /&gt;
   &lt;attribute name="location" type="string" /&gt;
   &lt;attribute name="Description" type="string" /&gt;
   &lt;attribute name="CreationDate" type="string" /&gt;
  </code></pre>
  
  <p>This my schema:</p>
  
  <pre><code> &lt;element name="Project" type="tns:Layer"&gt;&lt;/element&gt;
  
   &lt;complexType name="Layer"&gt;
          &lt;sequence&gt;
              &lt;element name="LayerName" type="string" maxOccurs="1"
                  minOccurs="0"&gt;
              &lt;/element&gt;
              &lt;element name="Order" type="integer"&gt;&lt;/element&gt;
              &lt;element name="Visible" type="boolean"&gt;&lt;/element&gt;
          &lt;/sequence&gt;
          &lt;attribute name="id" type="integer"&gt;&lt;/attribute&gt;
      &lt;/complexType&gt;
  </code></pre>