doc: update the community page

[msgui]

Subtask of #257, we could use a TODO tag to check the status: (click the button directly to mark it as done)

• [x] update the EN&CN community page
• [x] update the EN page with README in subscriber page
• [x] update the EN page with README in subscriber-cn page & translation
• [x] enhance the content with GPT/New Bing
• [x] update the README info

After:

[imbajin]

@msgui some improvement: [TODO]

1. remove extra unsubscribe desc here

2. UI not unify in EN/CN

3. hide outdated articles & add the TODO comment in parent page

   

4. capitalize the letter