Deploy document on release by github actions

[Yang-33]

https://github.com/line/line-bot-sdk-php/pull/522 tried to update document and push changes to master branch. However it doesn't work because github actions can't push changes to protected branch.

• https://github.com/orgs/community/discussions/25305
• https://github.com/orgs/community/discussions/13836
• https://stackoverflow.com/questions/74128344/github-protected-branch-hook-declined-even-with-allow-force-pushes

Thanks to https://github.com/actions/deploy-pages, we can deploy & run github pages on release probably. Let's try!