#1402 Environment variables for custom image (#1403)

* chore: enhance compose.yaml with variables for customize

* chore: use default blank values for db and redis variables in compose.yaml

* chore: Use env var for HTTP(S) publish ports in overrides

* docs: explain use of environment variables for image customization

* chore: use ERPNEXT_VERSION as default

* docs: fixed spelling errors

overrides/compose.https.yaml

@@ -21,8 +21,8 @@ services:
       - --certificatesResolvers.main-resolver.acme.email=${LETSENCRYPT_EMAIL:?No Let's Encrypt email set}
       - --certificatesResolvers.main-resolver.acme.storage=/letsencrypt/acme.json
     ports:
-      - 80:80
-      - 443:443
+      - ${HTTP_PUBLISH_PORT:-80}:80
+      - ${HTTPS_PUBLISH_PORT:-443}:443
     volumes:
       - cert-data:/letsencrypt
       - /var/run/docker.sock:/var/run/docker.sock:ro