Serving Files with Network-First Policy

Let's replace the fetch event handler in serviceworker.js to use now the algorithm known as Network first.

self.addEventListener("fetch", async event => {
    event.respondWith(

        (async () => {
            try {
                const fetchResponse = await fetch(event.request);
                return fetchResponse;
            } catch (e) {
                const cachedResponse = await caches.match(event.request);
                if (cachedResponse) return cachedResponse;
            }
        })()

    );
});