Improve README

Author: andyone

README.md

@@ -50,7 +50,7 @@ bash <(curl -fsSL https://apps.kaos.st/get) sslcli
 The latest version of `sslcli` also available as Docker image on [Docker Hub](https://kaos.sh/d/sslcli) and [GitHub Container Registry](https://kaos.sh/p/sslcli):
 
 ```bash
-docker pull essentialkaos/sslcli
+docker pull essentialkaos/sslcli:latest
 docker run --rm -it essentialkaos/sslcli:latest mydomain.com
 ```