Feat: add dockerfile entrypoint use cmd

Dockerfile

@@ -32,4 +32,6 @@ EXPOSE 8080/tcp 8080/udp
 
 VOLUME [ "~/.synctv" ]
 
-CMD [ "/entrypoint.sh" ]
+ENTRYPOINT [ "/entrypoint.sh" ]
+
+CMD [ "server" ]

script/entrypoint.sh

@@ -4,4 +4,4 @@ chown -R ${PUID}:${PGID} ~/.synctv
 
 umask ${UMASK}
 
-exec su-exec ${PUID}:${PGID} synctv server --env-no-prefix
+exec su-exec ${PUID}:${PGID} synctv --env-no-prefix $@