rss.php inside theme folder

<?php
/**
* Template Name: Google News Feed RSS
*/
//$postCount = 50;
//$posts = query_posts('category__not_in=1,46&showposts=' . $postCount);
$args_gnr = array(
'post_type' => 'post',
'post_status' => 'publish',
'category__not_in' => array(1),
'showposts' => 50,
'orderby' => 'date',
'order' => 'DESC',
'post_status' => 'publish',
'post_type'=>'post'
);
$query_gnr = new WP_Query( $args_gnr );
header('Content-Type: '.feed_content_type('rss-http').'; charset='.get_option('blog_charset'), true);
echo '<?xml version="1.0" encoding="UTF-8"?>';
?>
<rss version="2.0"
xmlns:content="http://purl.org/rss/1.0/modules/content/"
xmlns:media="http://search.yahoo.com/mrss/"
xmlns:wfw="http://wellformedweb.org/CommentAPI/"
xmlns:dc="http://purl.org/dc/elements/1.1/"
xmlns:atom="http://www.w3.org/2005/Atom"
xmlns:sy="http://purl.org/rss/1.0/modules/syndication/"
xmlns:slash="http://purl.org/rss/1.0/modules/slash/"
<?php do_action('rss2_ns'); ?>>
<channel>
<title>Website.com</title>
<atom:link href="<?php self_link(); ?>" rel="self" type="application/rss+xml" />
<link>https://www.website.com</link>
<description>Website description</description>
<lastBuildDate><?php echo get_feed_build_date( 'r' ); ?></lastBuildDate>
<language>hr</language>
<sy:updatePeriod>hourly</sy:updatePeriod>
<sy:updateFrequency>1</sy:updateFrequency>
<image><title>Racunalo.com</title><url>https://www.website.com/logo_rss.png</url><link>https://www.website.com</link><width>125</width><height>40</height><description>Publikacije i vijesti iz svijeta poslovanja i tehnologije</description></image>
<?php if($query_gnr->have_posts()): while($query_gnr->have_posts()): $query_gnr->the_post(); ?>
<item>
<title><?php the_title_rss(); ?></title>
<link><?php the_permalink_rss(); ?></link>
<pubDate><?php echo mysql2date('D, d M Y H:i:s +0000', get_post_time('Y-m-d H:i:s', true), false); ?></pubDate>
<dc:creator><?php the_author(); ?></dc:creator>
<?php
$thumbnail_ID = get_post_thumbnail_id($post->ID);
$thumbnail = wp_get_attachment_image_src($thumbnail_ID, 'thumb');
$mime_vrsta =  get_post_mime_type( $thumbnail_ID );
?>
<media:content url="<?php echo $thumbnail[0]; ?>" type="<?php echo $mime_vrsta; ?>" expression="full" width="1200" height="675">
<media:description type="plain">
<![CDATA[Photo desc - <?php the_title_rss(); ?>]]>
</media:description>
<media:credit role="author" scheme="urn:ebu">
<![CDATA[Website.com - <?php the_author(); ?>]]>
</media:credit>
</media:content>
<?php the_category_rss( 'rss2' ); ?>
<guid isPermaLink="false"><?php the_guid(); ?></guid>
<description><![CDATA[<?php the_excerpt_rss(); ?>]]></description>
<?php
//$content = get_the_content_feed( 'rss2' );
//$content = apply_filters( 'the_content', get_the_content() );
//$content = str_replace( ']]>', ']]&gt;', $content );
// code for spliting content after <h2>...</h2> to insert "AD block", which not parsed and displayed here
$sadrzaj = get_extended($post->post_content);
$sadrzaj['main'] = $sadrzaj['main'].'</h2>';
$prvi = apply_filters('the_content', $sadrzaj['main']);$sadrzaj['extended'] = $sadrzaj['extended'];
$sadrzaj['extended'] = str_replace('</h2>','',$sadrzaj['extended']);
$drugi = apply_filters('the_content', $sadrzaj['extended']);
$prvi_skoro = str_replace("</h2>\n</h2>","</h2>",$prvi);
//echo str_replace(".</p>","",$prvi_skoro);
$procisceni = str_replace('</h2><p>','<p>',$drugi);
?>
<content:encoded><![CDATA[<?php echo str_replace(".</p>","",$prvi_skoro); echo $procisceni; ?>]]></content:encoded>
<?php rss_enclosure(); ?>
<?php do_action('rss2_item'); ?>
</item>
<?php endwhile; endif; wp_reset_postdata(); ?>
</channel>
</rss>