Updated "windowsize" documentation; it didn't mention arbitrary sizes!

docs/html/OPTIONS.html

@@ -22,7 +22,7 @@ New Breed Software</p>
 <p><a href="mailto:bill@newbreedsoftware.com">bill@newbreedsoftware.com</a><br>
 <a href="http://www.tuxpaint.org/">http://www.tuxpaint.org/</a></p>
 
-<p>April 24, 2007</p>
+<p>April 25, 2007</p>
 </center>
 
 <hr size=2 noshade>
@@ -104,16 +104,22 @@ New Breed Software</p>
 
   <dt><code><b>windowsize=<i>SIZE</i></b></code></dt>
   <dd>
-    Run the program at a higher resolution, rather than the default of 640x480.
-    The <i>SIZE</i> value may be one of:
+    <p>Run the program at a different size (in windowed mode) or
+    at a different screen resolution (in fullscreen mode), rather than the
+    default (usually 800x600).</p>
+
+    <p>The <i>SIZE</i> value should be presented in pixels, in 'width-by-height'
+    format, with an "x" (lowercase&nbsp;X) between the values. The size can
+    be anything that's at least 640 wide, and at least 480 tall.</p>
+
+    <p>Some examples:
     <ul>
     <li>640x480
-    <li>800x600
     <li>1024x768
-    <li>1280x1024
-    <li>1400x1050
+    <li>768x1024
     <li>1600x1200
     </ul>
+    </p>
   </dd>
 
   <dt><code><b>nosound=yes</b></code></dt>