docker: rename docker-compose file.

Move the docker-compose file up to the root directory so you can just do
`docker-compose up` to bring up Danbooru.

config/docker/docker-compose.simple.yaml

@@ -1,55 +0,0 @@
-# A Docker Compose file that launches a minimal Danbooru instance. This is
-# suitable as a quick demo or for personal use, not for public-facing sites.
-#
-# Usage:
-#
-#     $ docker-compose -f config/docker/docker-compose.simple.yaml up
-#     $ docker-compose -f config/docker/docker-compose.simple.yaml down
-#
-# References:
-#
-# * https://docs.docker.com/get-docker/
-# * https://docs.docker.com/compose/install/
-# * https://docs.docker.com/compose/compose-file/compose-versioning
-# * https://docs.docker.com/compose/release-notes
-
-# Version 3.4 is the latest version that is supported by the version of Docker
-# Compose shipped with Ubuntu 18.04 LTS (version 1.17.4).
-version: "3.4"
-
-services:
-  danbooru:
-    image: evazion/danbooru
-    # build:
-    #  context: ../..
-    #  dockerfile: config/docker/Dockerfile.danbooru
-    ports:
-      - "80:3000"
-    environment:
-      - RAILS_ENV=production
-      - RAILS_SERVE_STATIC_FILES=true
-      - DATABASE_URL=postgresql://danbooru@postgres/danbooru
-      - DANBOORU_CANONICAL_URL=http://localhost
-    volumes:
-      - "danbooru-images:/danbooru/public/data"
-    depends_on:
-      - postgres
-    command: ["bash", "-c", "bin/rails db:setup; bin/rails server -b 0.0.0.0"]
-    user: root
-
-  postgres:
-    image: evazion/postgres
-    # build:
-    #  context: .
-    #  dockerfile: Dockerfile.postgres
-    environment:
-      POSTGRES_USER: danbooru
-      POSTGRES_HOST_AUTH_METHOD: trust
-    volumes:
-      - "danbooru-data:/var/lib/postgresql/data"
-
-volumes:
-  danbooru-images:
-    name: danbooru-images
-  danbooru-data:
-    name: danbooru-data