For reference: https://go.dev/ref/mod#major-version-suffixes
- Remove feed_icons cache because it's causing more problems that it solve. - Add basic offline mode when using the service worker. - Starting in Chrome 93, offline mode is going to be a requirement to install the PWA. https://developer.chrome.com/blog/improved-pwa-offline-detection/#enforcement-starting-chrome-93-august-2021