Update contribution message in letter.html

Author: dhowe

letter.html

@@ -80,7 +80,7 @@ <h3>HELP KEEP ADNAUSEAM ALIVE!</h3>
     on the table for our developers.
 </p>
 <p>
-    <b>You can contribute via our <a href="https://opencollective.com/adnauseam">Open Collective</a> page. And, we love hearing from you!</b>
+    <b>Contribute via our <a href="https://opencollective.com/adnauseam">Open Collective</a> page. And, we love hearing from you!</b>
 </p>
 
 </div>