Clarify 'content item'

[guardrex]

Description

Per dotnet/aspnetcore#44430 (comment)

Page URL

https://learn.microsoft.com/en-us/aspnet/core/blazor/components/virtualization?view=aspnetcore-8.0

Content source URL

https://github.com/dotnet/AspNetCore.Docs/blob/main/aspnetcore/blazor/components/virtualization.md

Document ID

26ed2425-63ec-e206-edcb-e51f17edb844

Article author

@guardrex