You might create several
<none> docker images during building a docker container. So cleaning up would be good for your local development environment because they might take your local storage.
There are two ways that you can clean up.
docker rmi $(docker images -f "dangling=true" -q)
If you are using Docker API(higher than 1.25) and you can use
docker image prune
By the way be careful to type it. If you add
-a option it will remove all your Docker images.