Improve bind:get/set coverage

[guardrex]

Fixes #36052

Distilled from Javier's remarks at dotnet/aspnetcore#57962 (comment).

Tom or Wade: Ready here! This is just mirroring some really nice remarks that Javier made in a PU discussion ☝️ that devs will likely find helpful in understanding why they shouldn't write directly to component parameters, favoring @bind:get/set directive attributes instead. This adds a little more juice to the existing section and example on binding across components. I only need one review to get this in.

For reference, here's one of the examples (because you can't see them here with the cross-repo links) ...

https://github.com/dotnet/blazor-samples/blob/main/10.0/BlazorSample_BlazorWebApp/Components/NestedChild.razor

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[Copilot]

Pull Request Overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated 1 comment.

[wadepickett]

Looks good! Approved.