Add 404 and 500 page

templates/error.html

@@ -1 +1,12 @@
-Error
+{% extends "base.html" %}
+{% block main %}
+    <div class="mt-4 text-center">
+        <h1>Oops ! An Error occured</h1>
+        <div class="alert alert-danger">
+          {% for error in state.errors %}
+            <p>{{ error }}</p>
+          {% endfor %}
+        </div>
+        <a href="/" class="mt-3 btn btn-info">Back to home</a>
+    </div>
+{% endblock %}