Oy.  I'm not so sure about this one.  The style that I was trying to keep to is that a simple indentation represents one-off example lines of code.  Possibly several together, but not in a coherent script.  See wcs.py for a bunch of these kinds of examples.

The `>>>` stuff (in my mind) was where the sequencing of the items mattered.  So for example, the GSParams example where I include the Traceback of the exception, or later in Airy and Kolmogorov where I show how `lam_over_diam` and `lam_over_r0` might be calculated.  Similarly Sersic has a bunch of these for the explanation of how the truncation works.  I don't think this look right without the `>>>` parts.

So I'd prefer to revert this commit and either add the `>>>` to the ones that don't have it, or at try to more carefully distinguish between the two kinds of code examples I described and follow that convention.  

There may be some things that currently have a `>>>` that don't need it according to that criteria.  But I think just removing all of them is not the right thing to do.