Code diffs don't show correct indentation

[johnpryan]

Describe the problem

Code snippets that use diff2html are not indented correctly.

Expected fix

I'm not sure how to fix this, or what could be causing this, but perhaps there is something we are doing wrong in our tooling.

On which platform(s) did you experience this issue?

macOS

Additional context

For example, see the Implicit animations page.

Screenshot:

[johnpryan]

cc: @parlough

[parlough]

I want to get rid of diff2html very soon, so perhaps with this issue I'll prioritize that.