FEATURE: add support for categories into content save/edit

resources/lang/cs/admin/contents.php

@@ -3,6 +3,7 @@ return [
 "alreadyHomepage" => "Domovská stránka",
 "appearance" => "Vzhled",
 "basicInfo" => "Základní informace",
+"category" => "Kategorie",
 "content" => "Obsah stránky",
 "deletePage" => "Smazat",
 "edit" => "Editace :name",

resources/lang/en/admin/contents.php

@@ -5,6 +5,7 @@ return [
     'status_protected'       => 'Protected',
     'status_public'          => 'Public',
     'new'                    => 'Create new :name',
+    'category'               => 'Category',
     'edit'                   => 'Edit :name',
     'editPlain'              => 'Edit',
     'content'                => 'Page content',

resources/lang/en/admin/history.php

@@ -12,6 +12,7 @@ return [
     'columnIs_homepage'        => 'Homepage',
     'columnParentPage'         => 'Parent page',
     'columnTitlePhotoFilename' => 'Title photo',
+    'columnCategory'           => 'Kategorie',
     'emptyValue'               => '<em>none</em>',
     'changedFromTo'            => 'Changed from <del>:from</del> to <ins>:to</ins>',
     'numOfChanges'             => 'One change|:count changes',