Show project hashtags prominently on project pages

Summary: Currently, it's unreasonably difficult for users to figure out some project hashtags because the rules aren't always intuitive.

Test Plan: {F174508}

Reviewers: chad

Reviewed By: chad

Subscribers: epriestley

Differential Revision: https://secure.phabricator.com/D9830

src/applications/project/controller/PhabricatorProjectProfileController.php

@@ -25,7 +25,8 @@ final class PhabricatorProjectProfileController
       ->setViewer($user)
       ->needMembers(true)
       ->needWatchers(true)
-      ->needImages(true);
+      ->needImages(true)
+      ->needSlugs(true);
     if ($this->slug) {
       $query->withSlugs(array($this->slug));
     } else {
@@ -280,6 +281,15 @@ final class PhabricatorProjectProfileController
       ->setObject($project)
       ->setActionList($actions);
 
+    $hashtags = array();
+    foreach ($project->getSlugs() as $slug) {
+      $hashtags[] = id(new PHUITagView())
+        ->setType(PHUITagView::TYPE_OBJECT)
+        ->setName('#'.$slug->getSlug());
+    }
+
+    $view->addProperty(pht('Hashtags'), phutil_implode_html(' ', $hashtags));
+
     $view->addProperty(
       pht('Members'),
       $project->getMemberPHIDs()