Update site design to incorporate new features (core values, news, digital assets, etc)

[bderfer68]

As a strategy stakeholder I want an overall site design that incorporates the new features we intend to add to the site, including an area to display our core values, an area to display digital assets like white papers, a separate "Careers" page, and a news area so that our site remains intuitive and easy to navigate while displaying the new features.

Note: we believe our audience, in priority order, is

1. Potential customers -- CORs and COs, Product Owners, Government Management, etc.
2. Potential future employees
   ---- big gap ------
3. Potential Partners

Prerequisite:

• Some idea of the content copy that will go into each section.
• Some minimal (at least) design system has been created based on the existing site

AC:

• General mockup is created for the site incorporating each of the changes that can be viewed for a variety of view sizes.
• Digital content and news are easy to upload, publish, and manage.
• Digital content and news can be found easily by people who want to learn more about A6 (but not necessarily pushed at them -- i.e. we want to see careers and jobs first).
• Possibly break "Careers" out into a separate page.
• As a digital content author, I can easily link to news or digital asset content from a variety of places (Slack, email, etc).
• The site still "hangs together" as a unified experience (i.e. we don't want new features to feel "tacked on.")