Homepage: Remove link to DOT site in "Stay up to date"

[esquared415]

In "Stay up to date" section at bottom right of Homepage, let's replace the link to Caltrans' version of Cal-ITP page (which DOT does not maintain) with a link to our site's Press page (which we will keep up to date).

• Please replace current text block under "Stay up to date" with:
  See our latest milestones on our Press page, and subscribe to the Caltrans Mobility Newsletter, a free biweekly resource with frequent Cal-ITP project updates.

CC: @mrose914