Update Bootstrap core CSS

Update with last stable version (5.1.3)

Author: ThibautPV

src/Views/layout.php

@@ -7,8 +7,8 @@
     <title><?= $this->renderSection('title') ?></title>
 
     <!-- Bootstrap core CSS -->
-    <link href="https://cdn.jsdelivr.net/npm/bootstrap@5.0.0-beta1/dist/css/bootstrap.min.css" rel="stylesheet" integrity="sha384-giJF6kkoqNQ00vy+HMDP7azOuL0xtbfIcaT9wjKHr8RbDVddVHyTfAAsrekwKmP1" crossorigin="anonymous">
-
+    <link href="https://cdn.jsdelivr.net/npm/bootstrap@5.1.3/dist/css/bootstrap.min.css" rel="stylesheet" integrity="sha384-1BmE4kWBq78iYhFldvKuhfTAU6auU8tT94WrHftjDbrCEXSU1oBoqyl2QvZ6jIW3" crossorigin="anonymous">
+    
     <?= $this->renderSection('pageStyles') ?>
 </head>