fix(deployments): fix broken config mount and expand env example

- Fix docker-compose.yaml: mount config.dev.yaml instead of nonexistent
  configs/config.yaml
- Add deployments/config.dev.yaml with Docker service names and dev
  defaults for zero-setup make docker-up
- Expand .env.example with all SILO_* and LDAP_* variables
- Update config.example.yaml hostnames to localhost with Docker comments
- Add deployments/config.docker.yaml to .gitignore (generated file)

deployments/docker-compose.yaml

@@ -69,7 +69,7 @@ services:
       - "8080:8080"
     volumes:
       - ../schemas:/etc/silo/schemas:ro
-      - ../configs/config.yaml:/etc/silo/config.yaml:ro
+      - ./config.dev.yaml:/etc/silo/config.yaml:ro
     healthcheck:
       test: ["CMD", "wget", "-qO-", "http://localhost:8080/health"]
       interval: 10s