Update docker installation

[rocky]

Install pymathics.natlang
Docker files are now in app not docker.

Down the line I'd like to see adding a simple script to run either the web and cli.

$ docker run --rm -it --name mathics-web -p 8000:8000 -v /tmp:/usr/src/app/data mathicsorg/mathics --mode ui
$ docker run --rm -it --name mathics-cli -v /tmp:/usr/src/app/data mathicsorg/mathics --mode cli

is a bit too tedious. Not sure how to get that done though.

[mmatera]

Maybe just add a docker-mathicsscript and docker-mathicsweb scripts to bin/?

[rocky]

Maybe just add a docker-mathicsscript and docker-mathicsweb scripts to bin/?

The problem here is that somehow we want this installed with docker. I suppose we could install docker-specific scripts inside Mathics3 even though those are supposed to be separate.

I may try this down the line in a different PR. Or feel free to do so yourself.

(I had originally posted a reply to a different question and removed that.)