Create "Features" page and link in site navigation

[kelynch]

Create a "features" page with the content in this Google doc.

Link to it in the site navigation, to the right of the "About" link, with a link called "Features"

New site navigation should look like this:

Acceptance criteria:

• [x] Create the new static "features" page
• [x] Add a link to the site navigation
• [x] Add a test