update tooltips message in upgrade docs

docs/upgrading.html

@@ -246,7 +246,7 @@
     <h1>Javascript plugins</h1>
   </div>
   <div class="alert alert-info">
-    <strong>Heads up!</strong> We're rewritten just about everything for our plugins, so head on over to <a href="./javascript.html">the Javascript page</a> to learn more.
+    <strong>Heads up!</strong> We've rewritten just about everything for our plugins, so head on over to <a href="./javascript.html">the Javascript page</a> to learn more.
   </div>
   <h3>Tooltips</h3>
   <ul>
@@ -255,6 +255,10 @@
     <li>The <code>animate</code> option was renamed to <code>animation</code>.</li>
     <li>The <code>html</code> option was removed, as the tooltips default to allowing HTML now.</li>
   </ul>
+  <h3>Tooltips</h3>
+  <ul>
+    <li>Values for <code>placement</code> option changed from <code>above</code> and <code>below</code> to <code>top</code> and <code>bottom</code>. (Affects popovers, too.)</li>
+  </ul>
   <h3>Popovers</h3>
   <ul>
     <li>Child elements now properly namespaced: <code>.title</code> to <code>.popover-title</code>, <code>.inner</code> to <code>.popover-inner</code>, and <code>.content</code> to <code>.popover-content</code>.</li>