fix command

README.md

@@ -148,7 +148,7 @@ docker run -it \
     -e GENERATE_UNIQUE=true \
     -e MASTER_PLIST_URL='https://raw.githubusercontent.com/sickcodes/osx-serial-generator/master/config-custom.plist' \
     -e SHORTNAME=sequoia \
-    docker-osx
+    sickcodes/docker-osx:latest
 ```
 
 #### Run Catalina Pre-Installed [![https://img.shields.io/docker/image-size/sickcodes/docker-osx/auto?label=sickcodes%2Fdocker-osx%3Aauto](https://img.shields.io/docker/image-size/sickcodes/docker-osx/auto?label=sickcodes%2Fdocker-osx%3Aauto)](https://hub.docker.com/r/sickcodes/docker-osx/tags?page=1&ordering=last_updated)