retake screenshots for showcase section

- take screenshots on computer with 3840x2400 resolution
- scale screenshots to 2564x1602 (2560x1600 with 2px border on sides and bottom)
- use clip-path to move tab in screenshot
- add script to squoosh generated images
- change aspect ratio to 16:10
- regenerate book image to have 16:10 aspect ratio w/ transparent 2px border on sides and bottom
- add support for specifying a role on a block image
- reduce top radius on screenshots; don't apply radius to book image
- slightly clean up CSS for positioning images
1 job for main in 34 seconds (queued for 4 seconds)
Status Name Job ID Coverage
passed lint #14617