Vercel deployment using your personal Github token

### Is your feature request related to a problem? Please describe.

The current deployment instructions for Vercel could use more clarity for users who want to deploy the project using their own GitHub token. This PR #4743 adds detailed steps, but it might be helpful to track improvements in an issue for discussion and further edits.

Users may be unsure whether to delete their GitHub token after deployment.
Instructions about environment variables in Vercel could be expanded for clarity.
Some users might be confused about contributions and branches when deploying.

### Describe the solution you'd like

Include a note on whether the GitHub token should be deleted after deployment.

Clarify which environment variables are required and how to add them in Vercel.

Mention whether contributions from a forked branch are counted on the original repository.

Optionally, add a step-by-step checklist for first-time deployers.

### Describe alternatives you've considered

_No response_

### Additional context

_No response_

Review PR #4743 and the current Vercel deployment instructions first. Update the documentation to cover token deletion, required Vercel environment variables, fork contributions, and an optional first-deployment checklist. Done means the deployment guidance answers each listed question clearly.

Written by the indexing model from the issue text.