Basic CI/CD for server docker images (sshd and sockd)

This creates a .gitlab-ci.yml file that creates two jobs when something is committed to main or based on a schedule. Those jobs will build the sshd and sockd docker images. If they fail to build then the jobs should like-wise fail and serve as a notice that something needs to be fixed.

I would recommend we setup a schedule to run weekly or a similar time frame to help catch issues that are created externally.

Below is the path were one could schedule thew new pipeline.

If desired we could setup similar for the most well used plugins.