Link back DockerHub page to this repo

[abitrolly]

Is your feature request related to a problem? Please describe

I'm always frustrated when I can not find source for Docker image because it is not linked from the DockerHub page.

https://hub.docker.com/r/gitpod/workspace-full

Describe the behaviour you'd like

Link back from https://hub.docker.com/r/gitpod/workspace-full here.