Add zure zsh completion to sheldon

sheldon-plugins.toml

@@ -43,4 +43,8 @@ use = ["modules/git/init.zsh", "init.zsh", "modules/completion/init.zsh"]
 
 [plugins.docker-cli]
 github = "docker/cli"
-use = ["contrib/completion/zsh/_docker"]
+use = ["contrib/completion/zsh/_docker"]
+
+[plugins.azure-cli]
+github = "azure/azure-cli"
+use = ["az.completion"]