Cleaning up README, removing Pipfile as it is no longer needed. Fixing Makefile after last renaming.

Removing local dependencies to create the TatSu parser, generating the grammar inside the docker container.

The development server uses docker-compose run and mounts the
app directory. It then runs the flask development server.
The production server uses docker-compose up and runs flask as a
uwsgi app behind nginx. It does not mount app.

Additionally, the grammar now uses custom semantics and creates flat
structures.