Create structure and publish current state-script example implementations

The intention is provide a couple of example state-scripts, part of the Mender client source repository.

This task covers to create the initial structure and publishing the ready-made script that we currently have. Separate task /eipic is to be created to add more use-case examples covering most of the examples that we provide in our docs

The intention of this is to provide read-made scripts that not necessarily cover all cases but at least can server as a starting point.

Acceptance criteria:

• Create PR to mendersoftware/mender with the initial structure and at least one example
• Link from docs to example implementations