docker(libervia): build site in the image: this will avoid a build each time the container starts fresh (notably with tests), as this is time and resource consuming (notably with node modules which would need to be downloaded each time).

version: "3.6"
services:

  sat:
    image: salutatoi/sat
    build: backend

  libervia:
    image: salutatoi/libervia
    build: libervia
    depends_on:
      - sat