update README.md add app-code in docker project

docker/php/Dockerfile

@@ -1,9 +1,18 @@
 FROM php:8.4-fpm
 
+ARG USER_ID=1000
+ARG GROUP_ID=1000
+
 RUN apt-get update && apt-get install -y \
-    git unzip libzip-dev libpng-dev libonig-dev \
+    git unzip libzip-dev libpng-dev libonig-dev gosu \
     && docker-php-ext-install pdo_mysql zip pcntl
 
+RUN if [ ${USER_ID:-0} -ne 0 ] && [ ${GROUP_ID:-0} -ne 0 ]; then \
+    groupmod -g ${GROUP_ID} www-data && \
+    usermod -u ${USER_ID} -g ${GROUP_ID} www-data \
+;fi
+
+
 COPY --from=composer:2 /usr/bin/composer /usr/bin/composer
 
 COPY entrypoint.sh /usr/local/bin/entrypoint.sh