feat: Improve Docker setup

- Remember credentials between container starts
- Use same uid/gid in container as on host

Dockerfile

@@ -14,6 +14,5 @@ FROM base
 
 COPY --from=builder /install /usr/local
 COPY zspotify /app
-COPY *zs_config.json /
 WORKDIR /app
 ENTRYPOINT ["/usr/local/bin/python", "__main__.py"]