title: Does pwa uses browser cache if their is no service worker
body: <p>I have an app written in js. I want to convert it to a pwa without a service worker . By adding manifest file I can add it from home screen and open it in full screen mode. Does it still using http caching If enabled or it will fetch request from network every time as I don’t have any service worker .
  Secondly how can I provided updated change in manifest file to an already installed pwa in ios.</p>