replaced 'bootstrap_v5.min.css' with all files in 'vendor/bootstrap/'

uitwww/templates/layout.html

 {# Source code of the Ubuntu-it website
 # Copyright (C) 2015 Pietro Albini <pietroalbini@ubuntu.com>
-# Copyright (C) 2023 shadMod
+# Copyright (C) 2023 shadMod <m.allegro@shadmod.com>
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU Affero General Public License as published
@@ -27,9 +27,16 @@
 	<meta name="viewport" content="width=device-width, initial-scale=1"/>
 
 	<link rel="shortcut icon" href="{{ url_for('static', filename='favicon.ico') }}">
+	<!-- static ubuntu css -->
 	<link rel="stylesheet" href="https://static.ubuntu-it.org/fonts/ubuntu/include.min.css">
 	<link rel="stylesheet" href="https://static.ubuntu-it.org/themes/italy/theme.min.css">
-	<link rel="stylesheet" href="{{ url_for('static', filename='assets/vendor/bootstrap_v5.min.css') }}">
+	<!-- bootstrap vendor css -->
+	<link rel="stylesheet" href="{{ url_for('static', filename='assets/vendor/bootstrap/colors.min.css') }}">
+	<link rel="stylesheet" href="{{ url_for('static', filename='assets/vendor/bootstrap/format_text.min.css') }}">
+	<link rel="stylesheet" href="{{ url_for('static', filename='assets/vendor/bootstrap/grid.min.css') }}">
+	<link rel="stylesheet" href="{{ url_for('static', filename='assets/vendor/bootstrap/layout.min.css') }}">
+	<link rel="stylesheet" href="{{ url_for('static', filename='assets/vendor/bootstrap/root.min.css') }}">
+	<!-- custom lib css -->
 	<link rel="stylesheet" href="{{ url_for('static', filename='assets/libs/main.min.css') }}">
 
 	{% block extra_header %}{% endblock %}