Javadoc fixes.

core/src/main/java/com/threerings/whirled/spot/package.html

@@ -95,9 +95,9 @@
       providing top-down 2D display of its scenes. <br>
     </p>
 
-    <center>
-      <img align="center" src="images/scene.png" alt="Example scene image">
-    </center>
+    <p>
+      <img src="images/scene.png" alt="Example scene image">
+    </p>
 
     <p> The arrows would, of course, not be rendered but are shown to
       indicate the presence of locations (and portals) and their