Draft: moves python to docker in dev-environment

Resolves Issue Set up the development environment in Docker (#282) • Torben Wittek

Summary:

• Python and PIP added to docker-compose-dev.yml to simplify local development
• hot-reloading realised with watchdog to maintain hot-reload in the docker container
• customised some configs to enable this

Open To Dos:

• adapt prerequisites in readme (also: isn't node also a prerequisite?)
• test the config on other devices to make sure everything works.