Add repository links to build settings

[sliverc]

trafficstars

Base image has been updated as I see at https://hub.docker.com/r/telemark/docker-node-unoconv/ but docker-unoconv-webservice is not being rebuilt.

I assume therefore that there is no repository link added on Docker Hub that this happens automatically.

See https://docs.docker.com/docker-hub/builds/#repository-links how to do so.