TCCP: Landing page illustration (for testing)

[chosak]

This commit adds an illustration to the TCCP landing page.

This code is being added for testing purposes and has a few things that will need to be cleaned up later if we want to go with this.

Screenshots

Notes and todos

With this change we can cleanup some of the custom CSS we were using to have icons in the landing page feature list. Also my use of image_passthrough here is hacky and copied from how we did it for the home page; this can be consolidated.

Checklist

• PR has an informative and human-readable title
• Changes are limited to a single goal (no scope creep)
• Code follows the standards laid out in the CFPB development guidelines
• Future todos are captured in comments and/or tickets