Add site previews on Pull Request

[hacksburg-john]

When making a PR (specifically updating the posts.json) generate the index.html and publish so that formatting and content can be checked.

Requirements:

• Only publish home page, other pages change infrequently and this will speed up deployments and reduce size
  • Specifically want to avoid duplicating 360 tour (many relatively large images)

Proposed framework using github actions:

1. On PR open, reopen, or synchronize with changes to posts.json
2. Checkout the PR branch
3. Run build script
4. Commit built html file to master (rename to PR-.html)
   • Optionally commit to a separate "preview" repo to keep master clean
5. Configure, upload, and deploy master to Github pages
6. Add comment with link to the page preview on the PR
7. On PR close, delete the preview file

[hacksburg-john]

Findings so far:

• Deploying the master branch from a dev branch takes additional effort. For initial prototyping, needed to manually trigger the master deployment script
• With the master branch protected agains pushes, github actions cannot commit to master. Can that user be allowed to push? May allow anyone to define an action that pushes to master, defeating the point...