TLS/1.3 information should be added to the TLS documentation

Today this document talks about TLS/1.2 quite a bit but there's very little content on TLS/1.3 and it's hard to understand how to update an app targeting the .NET Framework to ensure TLS/1.3 is enabled.

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#### Document Details

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* ID: 7341fa0a-f474-6c2d-d3c0-7e2df12fbb65
* Version Independent ID: e99c489a-7518-d293-ad93-7eaca8b7191a
* Content: [Transport Layer Security (TLS) best practices with the .NET Framework - .NET Framework](https://learn.microsoft.com/en-us/dotnet/framework/network-programming/tls)
* Content Source: [docs/framework/network-programming/tls.md](https://github.com/dotnet/docs/blob/main/docs/framework/network-programming/tls.md)
* Product: **dotnet-framework**
* Technology: **dotnet-networking**
* GitHub Login: @karelz
* Microsoft Alias: **ncldev**