Added Spice.add() overview, fixed spice_templates.md TODO list
Revert "Reorder Goodie files: tutorial -> testing -> further details"

This reverts commit a632bcb8d3fbcab8ba1b6c53c29d9785adf6ed36.
Moving this change to a seperate PR
Revert "Reorder Spice files, basic tut -> testing -> further deatils"

This reverts commit d6bfa428120d440a4b0e579e712b91103d1cd759.
Moving this to a different PR