feat(templates/403.html): add template for 403

kursy/templates/403.html

@@ -0,0 +1,14 @@
+{% extends "base.html" %}
+{% load i18n %}
+
+{% block title %}Page not found{% endblock %}
+
+{% block body_class %}template-403{% endblock %}
+
+{% block content %}
+<div class="text-center py-10">
+  <h1 class="text-4xl text-red-800">{% trans "Forbidden" %}</h1>
+
+  <h2>{% trans "Sorry, you don't have permission to access this page." %}</h2>
+</div>
+{% endblock %}