Support webpacker live-reloading on Docker (#26419)

.devcontainer/docker-compose.yml

@@ -25,6 +25,7 @@ services:
     command: sleep infinity
     ports:
       - '127.0.0.1:3000:3000'
+      - '127.0.0.1:3035:3035'
       - '127.0.0.1:4000:4000'
     networks:
       - external_network