chore(docs): move translated docs into docs/i18n/ (#3621)

* chore(docs): move translated docs into docs/i18n/

Collect the translated README/QUICKSTART/CONTRIBUTING/MAINTAINERS files
(including the Korean set) into docs/i18n/, leaving only the English sources
in the repo root so the GitHub project home page file list stays clean.
Rewrite internal links for the new layout (../../ for repo-root resources,
sibling filenames between translations), update both switcher conventions,
the i18n-check mixed-layout support, the contributors-wall workflow globs,
TRANSLATIONS.md guidance, and drop now-dead root translation paths from the
fork-PR docs allowlist.

* fix(docs): correct root-relative links in Korean contribution guide

Prefix repo-root targets (scripts/sync-design-systems.ts, TRANSLATIONS.md,
package.json, .github/pull_request_template.md) with ../../ so they resolve
from the new docs/i18n/ depth; sibling translated docs stay bare.

Generated-By: looper 0.8.1 (runner=fixer, agent=claude-code)

---------

Co-authored-by: qiongyu1999 <2694684348@qq.com>

.github/workflows/refresh-contributors-wall.yml

@@ -30,12 +30,13 @@ jobs:
       - name: Refresh cache bust date
         run: |
           DATE="$(date -u +%F)"
-          MATCHES="$(perl -0ne '$count += () = /cache_bust=\d{4}-\d{2}-\d{2}/g; END { print $count + 0 }' README*.md)"
+          README_FILES=(README.md docs/i18n/README.*.md)
+          MATCHES="$(perl -0ne '$count += () = /cache_bust=\d{4}-\d{2}-\d{2}/g; END { print $count + 0 }' "${README_FILES[@]}")"
           if [ "$MATCHES" -eq 0 ]; then
             echo "Warning: No cache_bust patterns found. README format may have changed."
             exit 1
           fi
-          perl -0pi -e "s/cache_bust=\d{4}-\d{2}-\d{2}/cache_bust=$DATE/g" README*.md
+          perl -0pi -e "s/cache_bust=\d{4}-\d{2}-\d{2}/cache_bust=$DATE/g" "${README_FILES[@]}"
 
       - name: Generate Open Design bot token
         id: open-design-bot-token
@@ -52,7 +53,9 @@ jobs:
         uses: peter-evans/create-pull-request@v8
         with:
           token: ${{ steps.open-design-bot-token.outputs.token }}
-          add-paths: 'README*.md'
+          add-paths: |
+            README.md
+            docs/i18n/README.*.md
           branch: automation/refresh-contributors-wall
           delete-branch: true
           commit-message: 'docs(readme): refresh contributors wall'