docs/migration guide: incorrect code diff highlight generated

[leumasme]

Describe the bug

On the migration guide page of the docs, this code can be seen with visual highlights on added/removed code, explaining the code changes between $: and runes.

This highlighting is incorrect, the "count" variable should not be highlighted as added. The green highlight should end earlier.
In the .md file backing this docs page (both on github and when inspecting browser requests), the highlight markers seem to be correctly placed:
https://github.com/sveltejs/svelte/blob/main/documentation/docs/07-misc/07-v5-migration-guide.md?plain=1#L35
---$:--- +++const+++ double = +++$derived(+++count * 2+++)+++;
The count variable is not between the +++ highlighting markers, and should thus already not be highlighted in green; something appears to be going wrong in creating the highlights in the browser based on the md file.

Reproduction

https://svelte.dev/docs/svelte/v5-migration-guide#Reactivity-syntax-changes-$:-$derived-$effect

Logs

No response

System Info

Chrome 131.0.6778.86

Severity

annoyance

[Ocean-OS]

I'm not entirely sure, but I think this issue should probably be moved to svelte.dev's repo, because this seems more like a markdown rendering issue rather than a documentation issue.