fix a typo
fix a typo

when i was using:
docker search --automated -s 3 nginx
told me:
Flag --automated has been deprecated, use --filter=automated=true instead
Flag --stars has been deprecated, use --filter=stars=3 instead
and when i use:
docker search --filter=automated=true --filter=stars=3 nginx
told me:
Error response from daemon: Invalid filter 'automated'
and i found out that the correct command should be:
docker search --filter=is-automated=true --filter=stars=3 nginx

Signed-off-by: Pure White <6b5b7bbb58e64cb988c01fba593337a1753ffcdd@126.com>

allencloud/cli,redpanda/cli,ashfall/cli,Zebrilee/cli,dnephin/cli,cpuguy83/cli,docker/cli,thaJeztah/cli,e11137/cli,riyazdf/cli,allencloud/cli,gdevillele/cli,thaJeztah/cli,dnephin/cli,riyazdf/cli,ashfall/cli,e11137/cli,Zebrilee/cli,redpanda/cli,cpuguy83/cli,docker/cli