Feature request: support additional capabilities

[GoudronViande24]

Make it so we can add additional capabilities. It would look like this in a docker-compose.yml file:

version: "3"

services:
  supercoolservice:
    image: node:latest
    ports:
      - "80:80/tcp"
    environment:
      TZ: 'America/Chicago'
    cap_add:         # THIS
      - NET_ADMIN    # THIS
    restart: unless-stopped