Break out middle part of original coordinates tutorial then delete it

[adrn]

PR #179 split up the original coordinates tutorial, so we should remove the original, long tutorial and make sure that all of the content has made it in to other tutorials.

[eteq]

@eblur - just wanted to confirm: this was the intent in #179, right? And maybe you did what @adrn said here (ensured everything was moved over) already in #179? (if not the to-do in this is to double-check it before removing)

[eteq]

Aha, after some sleuthing I realized that we are not ready to do this, because the middle part of the original tutorial is not yet in a separate tutorial. That is, we have the intro and transforming part, but not the coordinates-matching part.

So I will rename this issue to what actually needs to be done, and assign myself for now.