Modify job description

* Swap section order (tell people who we are and where we are before telling them what we do)
* Update address
* Update stack information (-Java, +Jenkins, etc)
* Reduce formatting noise for non-markdown layouts
* Change core hours from 12pm- to 10:30pm-
* Merge full-time and co-op job descriptions; the similarities between the two are too small to justify two versions.