Spanish Quick Reference updated

Please see the original post or just view the quick reference (cf old version).

• Page 2: Improved clarity of pronunciation guide
• Page 3: Replaced necesitar and obtener with empezar (because it's irregular) and conseguir (it has nearly the same meaning as obtener but is more common). Added trivia about Spanish verb irregularities at the bottom.
• Page 4: corrected a mistake, improved clarity, added examples for se.