Migrate the code base from https://gitlab.com/dananglin/helix.git to https://forge.dananglin.me.uk/code/dananglin/helix.git
This commit adds the new containers stack which now builds the traefik docker image and creates the traefik docker container. Pulumi needed to be downgraded to version 3.2.1 because later versions panic when building the docker image.
The project name was updated in GitLab.
