Tags: bill9109/dsh-web-ui-notify

docs: adopt shared bilingual README convention + community files (v0.…

…1.3)

- README.md (English) becomes the main file, README.zh.md mirrors it; the
  previous README.md (zh) + README.en.md layout is renamed into that convention
- README.i18n.yaml records git blob hashes with scripts/verify-i18n.mjs
  (node scripts/verify-i18n.mjs --write after editing either side)
- README restructured: static badges, one-line install, Why this exists,
  install/upgrade/uninstall lifecycle, usage states, troubleshooting table,
  development and verification, community
- package.json: English description, keywords, engines, ./cordis.patch.yml
  export, README/CHANGELOG in files, homepage/bugs
- add CHANGELOG.md (Keep a Changelog), CONTRIBUTING.md, SECURITY.md,
  SUPPORT.md, CODE_OF_CONDUCT.md