Update dockerfile

dockerfile

@@ -1,11 +1,12 @@
-ln -s docker/{cpu/Dockerfile,cpu/docker-compose.yml,.dockerignore} .
-cp docker/.env.example .env
+FROM python:3.9
+RUN ln -s docker/{cpu/Dockerfile,cpu/docker-compose.yml,.dockerignore} .
+RUN cp docker/.env.example .env
 #Create logs/cache dir : 
-mkdir -p logs cache
+RUN mkdir -p logs cache
 # Edit .env and set: 
 #   TORCH_CUDA_ARCH_LIST based on your GPU model
 #   APP_RUNTIME_GID      your host user's group id (run `id -g` in a terminal)
 #   BUILD_EXTENIONS      optionally add comma separated list of extensions to build
 # Edit CMD_FLAGS.txt and add in it the options you want to execute (like --listen --cpu)
 # 
-docker compose up --build
+RUN docker compose up --build