Finish Spanish (Latin American) translation

The Spanish translation has been complete for a while: https://es-latam.futurecoder.io/course/

But it still needs a full proofreading. This means actually going through every step in the course, checking all the hints, and submitting code according to the instructions. It's easy for everything to *look* OK when actually some small translation mismatch means that apparently correct code doesn't pass the automatic checker. But there could also be typos and other mistakes that I have no way of detecting myself.

Finishing this would be incredibly valuable as it would allow announcing the Spanish translation publicly and linking to it from the English and French sites.