Spanish Revuo PDF added and library section review
Did some translations fixes, changed, and added some new text. In Spanish we don't have oxford commas, so they were removed. The letter "Q" stands for "quarter" and in Spanish, we know it as "trimestre", so it was changed to "T". In Mastering Monero section, "Preview" wasn't translated, so I added the translation "Vista previa". Added the PDF Spanish Revuo Monero, Q4 2017 and build from jekyll and everything looks good.
Thank you guys for your hard work.