I would like to second this request for Mayan EDMS.
There's currently a Docker container on docker hub (source on GitLab) but it doesn't support upgrading. I'm currently looking into it myself, but I think someone with more docker experience would be able to do it easily.
My best hope for it at the moment is for this pull request to go through on the nginx-proxy docker container. I managed to get nginx-proxy working on unRAID. I'll post my config in the other thread.
I had a look at your Apache container, and it doesn't do the same thing as jwilder/nginx-proxy.
Docker container IP addresses are randomised, and unRAID doesn't set a container hostname, so it looks like your Apache container config expects the host IP address in the ProxyPass config. jwilder/nginx-proxy uses docker-gen to read container meta-data and generate nginx confg files from that.
I attempted to run it using the Community Applications plugin to grab it from Docker Hub, but I couldn't get it to start up. It just exited with code 1, and there was nothing in the logs.