Add a "start with a template" option when creating dashboards

Summary: Ref T5317. This primarily makes it easier for new administrators to build a dashboard for the first time, without going too crazy on technical complexity.

Test Plan: See screenshots.

Reviewers: btrahan, chad

Reviewed By: chad

Subscribers: epriestley

Maniphest Tasks: T5317

Differential Revision: https://secure.phabricator.com/D9651

src/applications/dashboard/controller/PhabricatorDashboardManageController.php

@@ -101,6 +101,12 @@ final class PhabricatorDashboardManageController
       $dashboard,
       PhabricatorPolicyCapability::CAN_EDIT);
 
+    $actions->addAction(
+      id(new PhabricatorActionView())
+        ->setName(pht('View Dashboard'))
+        ->setIcon('fa-columns')
+        ->setHref($this->getApplicationURI("view/{$id}/")));
+
     $actions->addAction(
       id(new PhabricatorActionView())
         ->setName(pht('Edit Dashboard'))