Add a "start here" file to the extras menu

[maccallum]

This should be small, and list each of the support files (o.overview, o.expr.overview, basically everything in the extras folder), with a brief description of what's in them. This would probably be the featured page (or whatever it's called) for the package manager

[equilet]

This was my initial call to rename o.tutorial to o.home or similar. I'll ping you directly

[equilet]

removed links to other items from the tutorial home patcher and added o.start.here. This can function as a first-contact patch.