Docs: add moveoff

Signed-off-by: John Thornton <jthornton@gnipsel.com>
docs: minor reorg in the Spanish html index

This moves the Stepper Diagnostics from the Getting Started section to
the Integrator Manual section in the Spanish html index.

This makes the Spanish Getting Started section of the html index have
closer to the same contents as the Spanish Getting Started pdf document.

Signed-off-by: Sebastian Kuzminsky <seb@highlab.com>