clean up docker images daily and weekly

Here’s the crontab content I used

@daily docker rmi `docker images -f dangling=true -q`
@weekly  docker rmi `docker images -f 'reference=100.98.97.206/*/*-ui:*'  --format "{% raw %}{{.Repository}}:{{.Tag}}{% endraw %}"`

reference document

• https://docs.docker.com/engine/reference/commandline/images/#filtering