Make this look better while the page is loading

core/src/main/resources/hudson/PluginManager/_table.js

@@ -46,6 +46,8 @@ Behaviour.specify("#filter-box", '_table', 0, function(e) {
     e.onkeyup = applyFilter;
 
     (function() {
+        var instructionsTd = document.getElementById("hidden-by-default-instructions-td");
+        instructionsTd.innerText = instructionsTd.getAttribute("data-loaded-text");
         applyFilter();
     }());
 });

core/src/main/resources/hudson/PluginManager/table.jelly

@@ -77,8 +77,8 @@ THE SOFTWARE.
                 <j:set var="cache" value="${it.createCache()}"/>
                 <j:if test="${filtered == 'true'}">
                   <tr id="hidden-by-default-instructions">
-                    <td class="pane" colspan="5" align="center">
-                      ${%Use the search field above to search for available plugins.}
+                    <td class="pane" colspan="5" align="center" id="hidden-by-default-instructions-td" data-loaded-text="${%instructions}">
+                      ${%loading}
                     </td>
                   </tr>
                 </j:if>

core/src/main/resources/hudson/PluginManager/table.properties

@@ -51,3 +51,6 @@ ago={0} ago
 adoptThisPlugin=\
   <strong>This plugin is up for adoption!</strong> We are looking for new maintainers. \
   Visit our <a href="https://jenkins.io/doc/developer/plugin-governance/adopt-a-plugin/" target="_blank">Adopt a Plugin</a> initiative for more information.
+
+loading=Plugin list is loading...
+instructions=Use the search field above to search for available plugins.