Simplify application index page

[thekaveman]

Background

We expect most users to come in to the app through a direct link to their agency's entry page, In other words, via core:agency_index rather than core:index. Since every user has to eventually go through the agency entry page and will read the content, we'd like to simplify the view on the application index to help avoid confusion and direct the user into the main flow.

New look

Tasks

• Update the core.pages.index.content_title text in English and Spanish #433
• Remove all paragraph content from the viewmodel in core:index #432
• Render the two buttons side-by-side #431

[angela-tran]

Closing this issue since it was broken out into 3 separate issues.