Re-add channels page

src/main/resources/static/js/channels.js

@@ -0,0 +1,10 @@
+const channelNameInput = document.getElementById("channel-search");
+
+function onOpenOverlayButtonClick(event) {
+    event.preventDefault();
+    const channelName = channelNameInput.value.trim().toLowerCase();
+    if (channelName) {
+        const overlayUrl = `/view/${channelName}/broadcast`;
+        window.location.href = overlayUrl;
+    }
+}