Change label of mention-button

* "Mention" on users profile
* "Post to group" on group/forums profile

src/Content/Widget/VCard.php

@@ -68,6 +68,7 @@ class VCard
 		$follow_link      = '';
 		$unfollow_link    = '';
 		$wallmessage_link = '';
+		$showforum_link   = '';
 
 		$photo   = Contact::getPhoto($contact);
 
@@ -119,6 +120,10 @@ class VCard
 			'$unfollow_link'    => $unfollow_link,
 			'$wallmessage'      => DI::l10n()->t('Message'),
 			'$wallmessage_link' => $wallmessage_link,
+			'$showforum'        => DI::l10n()->t('Show forum'),
+			'$showforum_link'   => $showforum_link,
+			'$mentioning'       => DI::l10n()->t('Mention'),
+			'$post2group'       => DI::l10n()->t('Post to group'),
 		]);
 	}
 }