Overhaul deployment method

[ianhinder]

The current deployment method is very simplistic and can't be monitored/debugged by people other than Ian. I propose changing to a deployment method based on GitHub Actions with a self-hosted runner. This could be controlled and monitored from the repository Actions tab. Before doing this, though, I would first separate (#71) the code from the configuration, so that the code repository is not cluttered with deployment-related data for a specific site. This will make the skills graph more reusable.