Optimized dockerimage using jlink

[kappsegla]

An optimized build of jre can be created using jlink and then we can copy the output into an docker image.
Let us create a new Dockerfile named Optimized.Dockerfile while keeping the old one and add instructions into the optimized version for a minimal build.

When trying out an image with another name than Dockerfile we must tell docker build what filename to use.

docker build -f Optimized.Dockerfile .

[helenahalldiniths]

I will not be able to work with the projekt a lot today. I have done quite a lot of issues so if someone wants to do this issue, please go ahead!