refactor: simplify registry to basic setup

- Reduce to only registry:2 image
- Remove unnecessary configuration files
- Add basic .gitignore and env.example
- Keep only essential docker-compose configuration

config.yml

@@ -1,22 +0,0 @@
-version: 0.1
-log:
-  fields:
-    service: registry
-storage:
-  cache:
-    blobdescriptor: inmemory
-  filesystem:
-    rootdirectory: /var/lib/registry
-http:
-  addr: :5000
-  headers:
-    X-Content-Type-Options: [nosniff]
-auth:
-  htpasswd:
-    realm: basic-realm
-    path: /etc/docker/registry/auth/htpasswd
-health:
-  storagedriver:
-    enabled: true
-    interval: 10s
-    threshold: 3