:data-index="index" is incorrect in DynamicScrollerItem demo

[lizy0329-biubiubiu]

Clear and concise description of the problem

Suggested solution

key-field and index must be consistent otherwise the size of the computed could be 0.

// DynamicScroller
key-field="post_id"

// DynamicScrollerItem
:data-index="item.post_id"
:index="item.post_id"

Alternative

No response

Additional context

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Validations

• Read the docs.
• Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.