Add Container Deployments from GitHub Actions to deploy-from-github.md

[jtrugman]

Added instructions about how to build containers in github actions and deploy them to CapRover using the GitHub container registry

[githubsaturn]

Thanks for the PR!

This is marked as a draft - assuming you're still working on it. Let me know once it's ready to review.

[jtrugman]

No problem! I appreciate the community's help with me deploying pre-built images using github actions!

I summarized the steps of what worked in the docs so future caprover users can learn how to do it from there. Please let me know your feedbacks.

[githubsaturn]

Thank you!!