Port specification - Dockerfile

[Teravla]

If you are launching several instances of pocketbase for different projects, it may be useful to create the Dockerfile just once, specifying the port

[KROSF]

At runtime you can map it to any host port you want, e.g.:

docker run -p 8081:8090 my-pocketbase
docker run -p 8082:8090 my-pocketbase