FeaturedThumbnailManager: add pager widget; show only 20 thumbs per page

templates/FeaturedThumbnailManager.php

@@ -21,8 +21,21 @@ class FeaturedThumbnailManager extends SubTemplate
 	{
 		echo '
 		<form action="" method="post">
-			<button class="btn btn-primary float-end" type="submit" name="changeThumbnail">Save thumbnail selection</button>
-			<h2>Select thumbnail</h2>
+			<div class="row">
+				<div class="col-lg">
+					<h2>Select thumbnail</h2>
+				</div>
+				<div class="col-lg">';
+
+		foreach ($this->_subtemplates as $template)
+			$template->html_main();
+
+		echo '
+				</div>
+				<div class="col-lg-auto">
+					<button class="btn btn-primary" type="submit" name="changeThumbnail">Save thumbnail selection</button>
+				</div>
+			</div>
 			<ul id="featuredThumbnail">';
 
 		foreach ($this->iterator as $asset)