Adds information from new Board elections

This PR makes several changes to update the Board and Governance page on the website:

 - Updates information for current Board members:
   - Daniel Izquierdo Cortázar (new title and bio)
   - Yuki Hattori (new title and bio)
   - Clare Dillon (new title)
   - Matt Cobby (new bio and photo)
   - Katie Schueths (moves to past member section)
   - Sebastian Spier (moves to past member section)
   - Tom Sadler (new title and moves to non-board elected officer section)
   - Georg Grütter (new title and moves to non-board elected officer section)
   - Danese Cooper (no changes)

Adds information for new members:
   - Jeff Bailey (title, bio, and photo)
   - Cristina Coffey (bio and photo)
   - Addie Girouard (bio and photo)
   - Jerry Tan (bio and photo)

This has been tested locally on my machine based on the dev environment directions in the repo's README.

Author: ElizabethN