Update index.php

On line #69 added id="selectedActionsList" to allow an easy adding of new actions customs apps wants to perform on selected files;

apps/files/templates/index.php

@@ -66,7 +66,7 @@
 					<input type="checkbox" id="select_all" />
 					<label for="select_all"></label>
 					<span class="name"><?php p($l->t( 'Name' )); ?></span>
-					<span class="selectedActions">
+					<span id="selectedActionsList" class="selectedActions">
 						<?php if($_['allowZipDownload']) : ?>
 							<a href="" class="download">
 								<img class="svg" alt="Download"