Move the Diff Complexity Icon story into a "Diffs" category.
Review Request #14143 — Created Sept. 5, 2024 and submitted — Latest diff uploaded
In preparation for new component stories for Storybook, this change does
a bit of preemptive reorganization, moving the Diff Complexity Icon into
a "Diffs" sub-category of "Components". This will help separate it from
other stories built in the future.
Re-ran Storybook and saw that the component was in the new category.