Add documentation for Docker images

[pascalberger]

We should add documentation for Docker images

[NamanPatidar]

Yes i am interested .

[Abhishekchauhan089]

I would like to work on this project

[pascalberger]

For anybody interested in this: Please read first through Cake Getting started section and README for Cake Docker images.

Scope of this issues is to document Docker images as a first class citizen for running Cake scripts, explaining the use cases for running Cake in a Docker container (mainly when using as a builder image). Having the possibility to run Cake in a Docker container should be documented at Running Cake Scripts page. Since the Docker image is basically a deployment unit for an existing runner, we should add additionally somewhere a dedicated page explaining how to use the Docker image as a builder image for building Docker containers.

@NamanPatidar @Abhishekchauhan089 Please let me know if you're still interessted in working on this issue considering the above explained scope.