[Pre4] Improve `OnNotFound` example

[guardrex]

Description

Per #35433 (comment), we'll have a better example.

Page URL

https://learn.microsoft.com/en-us/aspnet/core/blazor/fundamentals/routing?view=aspnetcore-10.0

Content source URL

https://github.com/dotnet/AspNetCore.Docs/blob/main/aspnetcore/blazor/fundamentals/routing.md

Document ID

b6cb2574-6326-a40d-0b6c-d1661328e828

Platform Id

4dcb037e-b606-e05a-a733-1458d2ce3914

Article author

@guardrex

Metadata

• ID: 35474d24-8039-f04a-de14-1530b8e8506c
• PlatformId: 4dcb037e-b606-e05a-a733-1458d2ce3914
• Service: aspnet-core
• Sub-service: blazor

Related Issues

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