ISIS Central Docs/Tutorial Page

[jrcain-usgs]

In migrating to the new docs website/separating out the docs into Getting Started, How-To, Concepts, and their subcategories, there's not currently as clear a direction to follow through all the ISIS tutorials.

I'm not quite sure where it belongs, maybe at the top of the Using ISIS: First Steps section, but I like this page from the ISIS Wiki: ISIS Online Workshops. It's a centralized page that links out (in a relatively good order to follow from start to finish) to a series of tutorials that you could go through, and by the end gain a good understanding of ISIS.