feat: add env variable to customize the proxy public ports

docker-compose.prod.yml

@@ -15,14 +15,14 @@ services:
       - ./data/logs/nginx/:/var/log/nginx
       - ./docker/certbot/certs/:/var/certs
     ports:
-      - "80:80"
-      - "443:443"
+      - "${PUBLIC_PROXY_PORT:-80}:80"
+      - "${PUBLIC_PROXY_SSL_PORT:-443}:443"
     tty: true
     depends_on:
       - server
       - webapp
 
-  webapp: 
+  webapp:
     container_name: bigcapital-webapp
     image: ghcr.io/bigcapitalhq/webapp:latest