- Replaced old “Install” links with new Mintlify installation pages.
- Updated “Build” links to point to the online building guide.
- Removed the extensive local build instructions and external control API
  sections from both English and Chinese READMEs as they are now outdated.
- Kept the remaining feature and discussion sections unchanged.

Signed-off-by: YumeLira <YumeLira@proton.me>