Add PWA support

It would be a killer feature if Logseq could offer a PWA application. I use ChromeOS, and it frustrates me to have to open Obsidian in a Linux container every time I want to jot down some text. I believe there are many users like me, and a PWA would definitely make the app more popular.

There was an experimental branch for PWA but AFAIK the idea is paused because Web browsers have not good enough API to access the storage the way Logseq needs to. Logseq started as an app that was supposed to run in the browser but because of those limitations the desktop app was introduced and the development focuses on it, while the Web version remains available as a demo at