Streamline default values

[tomh4]

It would be nice if the defaults of this helm charts would match the defaults of the docker image.
It took some time to figure out why things were not working for us,

is there a reason for these different defaults?
If so, there could at least be a little note in the readme to ease the transition from docker image to this helm chart

[DarthSim]

Hey @tomh4!

Could you tell which default values broke things for you?

[tomh4]

Hey,
So first of all the url signature which is off by default usually but not for the Helm chart
https://docs.imgproxy.net/configuration/options

And then the exposed port of the service which is exposed on 80 and not 8080

These two took me some time but I am sure there are others as well😊