Add "Deploy PR Preview" workflow

[yoren]

This pull request introduces automated previews for pull requests, allowing contributors and reviewers to view changes in a live environment before merging. The changes include a new GitHub Actions workflow to build and deploy PR previews, and updates to the documentation to explain the preview feature.

Resolves issue #3

PR Preview Automation

• Added .github/workflows/deploy-pr-preview.yml workflow to automatically build and deploy a Jekyll site preview for each pull request, and clean up the preview when the PR is closed.

Documentation Updates

• Updated README.md to document the new pull request preview feature, including instructions and preview URL format.

Demonstration

Before maintainers manually approve the workflow, it cannot be run. So I added a demo to my forked repo: https://github.com/yoren/wp-a11y-docs/pull/2

Repo Settings Updates

• May consider add: https://docs.github.com/en/actions/how-tos/manage-workflow-runs/approve-runs-from-forks

[yoren]

@rianrietveld To run the workflow it requires a maintainer's approval. I used a PR on my forked repo to demonstrate it. Let me know if we have a specific PR review process to follow and I'll update accordingly. Thanks!

[yoren]

@rianrietveld The deployment threw an error so can you pls help me check:

• Go to repository's settings on GitHub.
• Navigate to "Actions" > "General" > "Workflow permissions".
• Make sure "Read and write permissions" is selected for "Workflow permissions".

Basically should look like this: https://share.cleanshot.com/lrYyfPtJ

[rianrietveld]

Hey @yoren thanks for the PR!
I added you to the Documentation team, so you have write access to the repo.
And you don't have to use a fork and we can test it better.

[yoren]

ok let me see if things will go right if I don't use a fork. Closing this one for now