create roles template files and explainers

[saltydk]

We will use a docs page as the reference for creating various types of Saltbox/Sandbox roles. This needs to be kept up to date at all times.

[owine]

Just noting for posterity - standard role and multi-instance role. I can't think of anything else common enough to be worth it.

[keldian]

Web and non-web/headless role perhaps.