add Dockerfile

[Strubbl]

This adds a Dockerfile. I used it to make sure the addon works when using node.js 16. I used it via the commands:

sudo docker build -t $USER_bibbot .
sudo docker run -it --user 1000:1000 -v ./dist:/home/node/dist $USER_bibbot

[darkdragon-001]

Minor suggestion for the Docker command:

sudo docker build -t $USER_bibbot .
sudo docker run -it --rm --user $(id -u):$(id -g) -v ./dist:/home/node/dist $USER_bibbot