added "stickyHeader_zIndex" docs. Fixes #332

docs/index.html

@@ -1343,8 +1343,18 @@ $(function(){
       filter_serversideFiltering :  false,
 
       // *** stickyHeaders widget ***
-      // css class name applied to the sticky header
-      stickyHeaders : "tablesorter-stickyHeader",
+      // extra class name added to the sticky header row
+      stickyHeaders : '',
+      // number or jquery selector targeting the position:fixed element
+      stickyHeaders_offset : 0,
+      // added to table ID, if it exists
+      stickyHeaders_cloneId : '-sticky',
+      // trigger "resize" event on headers
+      stickyHeaders_addResizeEvent : true,
+      // if false and a caption exist, it won't be included in the sticky header
+      stickyHeaders_includeCaption : true,
+      // The zIndex of the stickyHeaders, allows the user to adjust this to their needs
+      stickyHeaders_zIndex : 2
 
       // *** resizable widget ***
       // if false, resized columns are not saved for next page reload
@@ -2147,6 +2157,28 @@ $('table').trigger('search', false);</pre></div>
 				<td></td>
 			</tr>
 
+			<tr id="widget-sticky-headers-zindex">
+				<td><a href="#" class="toggle2">stickyHeaders_zIndex</a></td>
+				<td>Numeric</td>
+				<td>2</td>
+				<td>
+					Sticky Headers widget: The zIndex added to the stickyHeaders. This option allows the user to adjust the value to their needs (<span class="version">v2.11</span>).
+					<div class="collapsible">
+					<br>
+					Use the <a href="#widget-sticky-headers-zindex"><code>stickyHeaders_zIndex</code></a> option as follows:
+					<pre class="prettyprint lang-javascript">$(function(){
+  $("table").tablesorter({
+    widgets: ["stickyHeaders"],
+    widgetOptions : {
+      // The zIndex of the stickyHeaders, allows the user to adjust this to their needs
+      stickyHeaders_zIndex : 100
+    }
+  });
+});</pre></div>
+				</td>
+				<td></td>
+			</tr>
+
 			<tr id="widget-resizable">
 				<td><a href="#" class="toggle2">resizable</a></td>
 				<td>Boolean</td>