feat: Added nginx container to docker compose file

deploy/docker/.env.example

@@ -17,4 +17,7 @@ KEY_ENCRYPTION_KEY=
 # MongoDB is bundled in this compose file. Override only to use an external DB.
 MONGO_URI=mongodb://mongo:27017/vantage
 
+# Host port the bundled nginx reverse proxy listens on (plain HTTP).
+NGINX_HTTP_PORT=80
+
 # Where workflow run logs are written inside the server container.