Add a direct link to class calendar on the header and footer sections

Add calendar link with path '/calendar' to Header and Footer components.

Replit-Commit-Author: Agent
Replit-Commit-Session-Id: d004b9e1-f9be-46e2-acda-f440ccd644a9
Replit-Commit-Screenshot-Url: https://storage.googleapis.com/screenshot-production-us-central1/af8dabca-e746-4e53-9c29-d8d4d9cf30f5/5a13f3d6-a7cc-40b0-9f95-c73bf929f745.jpg

client/src/components/navigation/footer.tsx

@@ -59,6 +59,14 @@ export default function Footer() {
                   Classes
                 </Link>
               </li>
+              <li>
+                <Link 
+                  href="/calendar" 
+                  className="text-white text-opacity-70 hover:text-white hover:text-opacity-100 transition duration-300"
+                >
+                  Calendar
+                </Link>
+              </li>
               <li>
                 <Link 
                   href="/community" 

client/src/components/navigation/header.tsx

@@ -25,6 +25,7 @@ export default function Header() {
     { name: "Home", path: "/" },
     { name: "About", path: "/about" },
     { name: "Classes", path: "/classes" },
+    { name: "Calendar", path: "/calendar" },
     { name: "Community", path: "/community" },
     { name: "Contact", path: "/contact" },
   ];