Permission for GitHub pages CICD

[donny-son]

SVG Web viewer 를 deploy 하기 위해서 write access 필요

/usr/bin/git push origin gh-pages
[83](https://github.com/statgarten/maps/actions/runs/3386464346/jobs/5625919431#step:3:89)
  remote: Permission to statgarten/maps.git denied to github-actions[bot].
[84](https://github.com/statgarten/maps/actions/runs/3386464346/jobs/5625919431#step:3:90)
  fatal: unable to access 'https://github.com/statgarten/maps.git/': The requested URL returned error: 403
[85](https://github.com/statgarten/maps/actions/runs/3386464346/jobs/5625919431#step:3:91)
  Error: Action failed with "The process '/usr/bin/git' failed with exit code 128"