Documentation: `Die arrangement and pads` is mostly blank

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The image at https://caravel-harness.readthedocs.io/en/latest/supplementary-figures.html#die-arrangement-and-pads appears to have two issues:

1. The image itself is cropped https://caravel-harness.readthedocs.io/en/latest/_images/die_pads.svg
2. The image is further cropped when displayed on the webpage: