Use sentence capitalization

wiki/src/donate.html

@@ -358,7 +358,7 @@ permitted by law.</strong></p>
   </div>
 
   <div class="col-md-7">
-    <h4>Bank Transfer</h4>
+    <h4>Bank transfer</h4>
     <p>
       <em>Account holder</em>: Center for Cultivation of Technology gGmbH<br/>
       <strong>Please make sure to mention the purpose of transfer.</strong>