Provide useful snippets

Summary:
shell/script.sh and python/command.py are intended as starting
point to create new commands

salt/file* contains headers needed for configuration files,
to stress the fact they are auto-generated and managed in rOPS.

Test Plan:

• shellcheck for shell/
• flake8 for python/

Reviewers: dereckson

Reviewed By: dereckson

Differential Revision: https://devcentral.nasqueron.org/D2954