Add node service to docker compose with run script

src/docker-compose.yml

@@ -38,3 +38,12 @@ services:
       - POSTGRES_DB=app
       - POSTGRES_USER=user
       - POSTGRES_PASSWORD=feedabee
+
+  node:
+    image: node
+    volumes:
+      - .:/app
+    working_dir: /app
+    stdin_open: true
+    tty: true
+    command: ./run_node_watch.sh

src/run_node_watch.sh

@@ -0,0 +1,15 @@
+#!/bin/bash
+npm install
+npm rebuild
+dir=./registrar/assets
+if [ -d "$dir" ]
+then
+  echo "Compiling USWDS assets"
+	npx gulp copyAssets
+  npx gulp compile
+else
+  echo "Initial USWDS assets build"
+  npx gulp init
+  npx gulp compile
+fi
+npx gulp watch