Investigate Storybook configuration to allow breakpoints to work

[natalia-fitzgerald]

In working through #572 we noticed an issue with the way the desktop hero with illustration is rendering in Storybook. This might be a global issue in Storybook but the purpose of this ticket is to track our investigation into the issue as it relates to the hero component.

In the hero with illustration:

• The hero image is filling the width and the height of the container.
• The illustration dimensions should be 470px wide (exact) and 195px high (maximum) (2x: 940px x 390px).

Screenshots

In production	DSR

In production	DSR

Other bugs:

• In the hero with photograph the photograph is not rendering.
• In the jumbo hero: Photo dimensions for small screens should be 600px (exact) x 338px (maximum) but it is rendering as 566px x 342.35px.