updated docs

docs/docs/howto_contribute.xml

@@ -17,7 +17,6 @@
          There are some simple ways to contribute to dlib:
 
          <ul>
-            <li> You could make a dlib logo </li>
             <li> Find confusing or incorrect documentation </li>
             <li> Help make the web page prettier </li>
             <li> Link to dlib from your web page </li>