feat: set up service worker for PWA

[xiaohanyu]

Description

Service worker sit at the core of a PWA app and we need to set up service worker when adopt PWA for PPResume.

This issue depends on #41 and is depended by #39

[Optional] Possible Solutions

• manually setup service worker
• use workbox to generate a service worker

Acceptance Criteria

• let's use workbox to generate a service worker for PPResume

Todo list

Tasks

Beta Give feedback

1. setup service-worker
2. setup correct caching strategy for different resources
3. make sure the app works the same with or without service worker cache (i.e, progressive enhancement)
4. check cachebility for cors request to unpkg
5. set cache quota and check cache eviction strategy

[xiaohanyu]

Done.

Preview: