Added Navbar

frontend/app/all-customers/page.tsx

@@ -0,0 +1,17 @@
+import { Button } from "@/components/ui/button";
+
+const page = () => {
+  return (
+    <div>
+      <p className="text-4xl font-medium">Customer List</p>
+      <div>
+        <p>Search Bar</p>
+        <Button>Add Customer</Button>
+      </div>
+
+      <div>A table of customers</div>
+    </div>
+  );
+};
+
+export default page;