Pontoon: Updated Spanish (es) localization of Pontoon Intro
Pontoon: Updated Spanish (es) localization of Pontoon Intro

Translation authors:
- Jeff Beatty <jbeatty@mozilla.com>

mathjazz/pontoon-intro,jotes/pontoon-intro,jotes/pontoon-intro,mathjazz/pontoon-intro,jotes/pontoon-intro,mathjazz/pontoon-intro