Describe the bug

Create a responsive image style for description list images at 1x and 2x. Use 439x222 as the default.

Steps to Reproduce

1. Visit the homepage
2. Scroll to Clients and Partners section
   
3. If you right click and inspect, you'll see that the images are actually 480x243
   

Expected behavior

Image should be consistently sized and account for both 1x and 2x screens.