Add PHPDocs generated by ChatGPT,

add additional clarification to some functions,
add addNewsComment function and API, currently untested and not implemented in the client,
fix a bunch of stuff that PHPStorm pointed out

lib/sitemap.php

@@ -1,8 +1,16 @@
 <?php
 require_once "lib/account.php";
-
-
-function generateSitemap(): void{
+/**
+ * Generates an XML sitemap as a string for a website, considering only pages that the current session
+ * has sufficient privileges to access. It scans directories specified in the router configuration
+ * for .html and .php files, and constructs a sitemap entry for each accessible page based on their
+ * required permission levels. This function returns the sitemap as a string and
+ * sets the appropriate header for XML content.
+ *
+ * @global array $routerConfig The global configuration array containing directory paths and default settings.
+ * @return string The XML sitemap content, properly formatted in accordance with the sitemap protocol.
+ */
+function generateSitemap(): string{
     global $routerConfig;
 
     $site_dirs = array_diff(scandir($routerConfig["page_dir"]), array('.', '..'));
@@ -54,5 +62,5 @@ function generateSitemap(): void{
     $sitemap .= '</urlset>' . PHP_EOL;
 
     header('Content-type: application/xml');
-    echo $sitemap;
+    return $sitemap;
 }