Light Freshness Edit: ASP.NET - Diagnostics + Hosts

[GitHubber17]

This PR contains light freshness updates to the following articles:

• Diagnostic code analysis in ASP.NET Core apps
• ASP.NET Core Web Host (duplicate content in moniker sections removed)
• .NET Generic Host in ASP.NET Core (duplicate content in moniker sections removed)

For details, see ADO request 568764.

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Internal previews

📄 File	🔗 Preview link
aspnetcore/diagnostics/code-analysis.md	customer intent: As an ASP.NET developer, I want to get details for specific diagnostic codes in ASP.NET Core, so I can understand the diagnostic messages in my apps.
aspnetcore/fundamentals/host/generic-host.md	.NET Generic Host in ASP.NET Core
aspnetcore/fundamentals/host/web-host.md	customer intent: As an ASP.NET developer, I want to explore the Web Host in ASP.NET Core, so I can configure startup and management for my web app.

[GitHubber17]

@tdykstra @wadepickett - Refreshed topics ready for review. See the top comment for details. Thank you.

Cc @cmastr

[wadepickett]

@GitHubber17, Looks great overall and a much improved article! There are couple important fixes to make, and then a few minor items. See inline comments with suggestions ready to commit.

[GitHubber17]

@wadepickett - Thank you for your review. I applied your suggested edits.

[wadepickett]

Looks great! Awesome work @GitHubber17!
Approved, merging...