Implement kiosk mode functionality and update external link handling in footer and credits

static/js/kiosk_mode.js

@@ -0,0 +1,13 @@
+document.addEventListener('DOMContentLoaded', () => {
+	setTimeout(() => {
+		// TODO: How to start kiosk mode?
+		if (true) {
+			console.info('Kiosk mode -> Disabled all external links');
+			document.querySelectorAll('a').forEach((link) => {
+				if (link.classList.contains('external-link')) {
+					link.style.pointerEvents = 'none';
+				}
+			});
+		}
+	}, 1000);
+});