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/dynamic_style.php

@@ -1,5 +1,11 @@
 <?php
-
+/**
+ * Generates dynamic CSS styling based on user preferences stored in the session.
+ * Specifically, it creates a CSS rule for the user's favorite color if it's specified in their session data.
+ *
+ * @return string Returns a string containing a `<style>` tag with custom CSS if a favorite color is set
+ *                and the user is logged in. Returns an empty string if no conditions are met.
+ */
 function doDynamicStyling() :string
 {
     $dynamic_style = "";