Changed source root directory

html/wp-content/plugins/mailchimp-for-wp/integrations/custom/admin-before.php

@@ -0,0 +1,15 @@
+<p>
+    <?php _e('To get a custom integration to work, include the following HTML in the form you are trying to integrate with.', 'mailchimp-for-wp'); ?>
+</p>
+
+<?php ob_start(); ?>
+<p>
+    <label>
+        <input type="checkbox" name="mc4wp-subscribe" value="1" />
+        <?php _e('Subscribe to our newsletter.', 'mailchimp-for-wp'); ?>
+    </label>
+</p>
+
+<?php $html = ob_get_clean(); ?>
+
+<textarea class="widefat code-sample" rows="<?php echo substr_count($html, PHP_EOL); ?>" readonly onfocus="this.select()"><?php echo esc_textarea($html); ?></textarea>