When a PR is raised, a preview app is created and shown as a comment in the pull request so that reviewer(s) may see the application

[chrisjsimpson]

Is your feature request related to a problem? Please describe.
When a PR is raised, a preview app is created and shown as a comment in the pull request so that reviewer(s) may see the application

Describe the solution you'd like

Describe alternatives you've considered

Additional context

• See example here (but also see newer, updated dokku official action which may be better suited now) https://github.com/Subscribie/subscribie/blob/master/.github/workflows/pr-demo-deploy.yml
• See "Review apps" in https://github.com/dokku/github-action#examples