Currently new users to the Chat a.k.a. Riot are presented with a wealth of information that has nothing to do with Degrowth.  Fortunately it seems Riot accepts a `welcomePageUrl` configuration parameter. We should be able to bundle a custom entry page with chat.degrowth.net and enable it via https://github.com/ecobytes/docker-matrix-riot/blob/master/config.degrowth.json#L17 https://chat.degrowth.net/home.html is a simple template, and then we may ease our deployment process also by using the upstream container as `FROM: ` and only injecting our configuration and additions via data volumes. https://github.com/ecobytes/docker-matrix-riot/blob/master/adds/start.sh#L5