Utilise GITHUB_TOKEN to commit to gh-pages and deploy

[dcshzj]

Part of reposense/RepoSense#1448.

Test action flow: https://github.com/dcshzj/publish-RepoSense/actions/runs/629123865
Generated report: https://dcshzj.github.io/publish-RepoSense/ (uses default values of this repository)

Users need to specify a personal access token or a deploy key to
automate the generation of the RepoSense report. This is an
additional step that makes using this repository less
user-friendly for new users.

Let's make use of the autogenerated GITHUB_TOKEN when using
GitHub Actions to automatically push to the gh-pages branch and to
trigger a GitHub Pages build.

[dcshzj]

I can't add reviewers on this repository, so pinging the team: @reposense/21-22-active-developer.

[HCY123902]

Can I ask whether the original personal access token will work after making this change?

[dcshzj]

No, we don't want to use the personal access token in GitHub Actions as the GitHub token is sufficient.

[HCY123902]

There seems to be some issue in the report in https://dcshzj.github.io/publish-RepoSense/ from my side. Is it intended or will it be possible that you can use this action flow to generate another report? Thanks

[dcshzj]

There seems to be some issue in the report in https://dcshzj.github.io/publish-RepoSense/ from my side. Is it intended or will it be possible that you can use this action flow to generate another report? Thanks

Yep, this is intended. This is due to the original settings of the report that only generates the report for the previous month, and is out of scope of this pull request.

[HCY123902]

LGTM

[dcshzj]

Pinging the next stage of reviewers: @reposense/stage-1-active-reviewer.

[dcshzj]

Re-pinging: @reposense/stage-1-active-reviewer