updated developing.md docs.

[suhalvemu]

I struggled in figuring out to set up local registry. So helping fellow developers with docs.

[Joxit]

Hi, thank you for using my project and contributing.

The example to use was the one in the README, the docker-compose example:

version: '3.8'

services:
  registry-ui:
    image: joxit/docker-registry-ui:main
    restart: always
    ports:
      - 80:80
    environment:
      - SINGLE_REGISTRY=true
      - REGISTRY_TITLE=Docker Registry UI
      - DELETE_IMAGES=true
      - SHOW_CONTENT_DIGEST=true
      - NGINX_PROXY_PASS_URL=http://registry-server:5000
      - SHOW_CATALOG_NB_TAGS=true
      - CATALOG_MIN_BRANCHES=1
      - CATALOG_MAX_BRANCHES=1
      - TAGLIST_PAGE_SIZE=100
      - REGISTRY_SECURED=false
      - CATALOG_ELEMENTS_LIMIT=1000
    container_name: registry-ui

  registry-server:
    image: registry:2.8.2
    restart: always
    environment:
      REGISTRY_HTTP_HEADERS_Access-Control-Allow-Origin: '[http://registry.example.com]'
      REGISTRY_HTTP_HEADERS_Access-Control-Allow-Methods: '[HEAD,GET,OPTIONS,DELETE]'
      REGISTRY_HTTP_HEADERS_Access-Control-Allow-Credentials: '[true]'
      REGISTRY_HTTP_HEADERS_Access-Control-Allow-Headers: '[Authorization,Accept,Cache-Control]'
      REGISTRY_HTTP_HEADERS_Access-Control-Expose-Headers: '[Docker-Content-Digest]'
      REGISTRY_STORAGE_DELETE_ENABLED: 'true'
    volumes:
      - ./registry/data:/var/lib/registry
    container_name: registry-server

[Joxit]

Line break

[Joxit]

So you still don't want to use a docker compose configuration right ? 😅