Add 'published' date to Atom feed entries

This change includes the 'published' date for each feed entry, using the post's creation timestamp. It enhances compliance with the Atom specification and provides more accurate metadata for feed consumers. Indentation inconsistencies in the file were also corrected for better readability.

src/themes/default/feed.php

@@ -5,7 +5,7 @@
 
 function escape(string $html): string
 {
-    return htmlspecialchars($html, ENT_XML1 | ENT_QUOTES | ENT_SUBSTITUTE);
+	return htmlspecialchars($html, ENT_XML1 | ENT_QUOTES | ENT_SUBSTITUTE);
 }
 
 header('Content-type: application/atom+xml');
@@ -26,13 +26,14 @@ function escape(string $html): string
 $Author->addChild('email', escape($config['author_email']));
 
 foreach ($data['posts'] as $bean) {
-    $Entry = $Xml->addChild('entry');
-    $Entry->addChild('id', Lamb\permalink($bean));
-    $Entry->addChild('title', escape($bean->title ?? ''));
-    $Entry->addChild('updated', date(DATE_ATOM, strtotime($bean->updated)));
-    $Content = $Entry->addChild('content', $bean->transformed);
-    $Content->addAttribute('type', 'html');
-    $Link = $Entry->addChild('link');
-    $Link->addAttribute('href', Lamb\permalink($bean));
+	$Entry = $Xml->addChild('entry');
+	$Entry->addChild('id', Lamb\permalink($bean));
+	$Entry->addChild('title', escape($bean->title ?? ''));
+	$Entry->addChild('published', date(DATE_ATOM, strtotime($bean->created)));
+	$Entry->addChild('updated', date(DATE_ATOM, strtotime($bean->updated)));
+	$Content = $Entry->addChild('content', $bean->transformed);
+	$Content->addAttribute('type', 'html');
+	$Link = $Entry->addChild('link');
+	$Link->addAttribute('href', Lamb\permalink($bean));
 }
 echo $Xml->asXML();