Update entities for docker container

[ElVit]

First of all THANK YOU for this integration. I have waited a long time for this 🙏.

Is your feature request related to a problem? Please describe.

One thing that always had bothered me was that my docker container became out of date in unraid.
Normally I check my home assistant dashboard every day.
But my my unraid dashboard maybe once a week or less often.

You showed also here and here that it is possible to trigger an update of all docker container via home assistant.
Usually I check first what changes are made before I install an updates, so I would like to have a bit more control than just update them all every night.
Unfortunatelly I could not find a way to check for updates...

Describe the solution you'd like

So it would be nice to have some kind of notification if there is a docker container update available in home assistant.
The best would be of course if we could have update entities for this 😃.

[domalab]

@ElVit Thanks for the feature request. I'm actually experimenting with a docker insights feature that's listed in #17.

I could look at extending it to provide what you are after.