Rework interactive tutorials

[BillWagner]

Fixes #50331

Reimagine the interactive tutorials that used Try.NET to introduce developers to the .NET platform.

Based on dotnet/try#1285, instead of Try.NET, use file-based apps in .NET 10 and GitHub codespaces to introduce developers to the platform without requiring an installation.

The current text uses the .NET template for the codespace. That works, but has extra features, and I'm working to get a new codespace for a minimal install. In the meantime, if you want to try the tutorials with the minimal set of features, open this (public) repository in codespaces: https://github.com/BillWagner/learn-csharp-codespaces

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Internal previews

📄 File	🔗 Preview link
docs/csharp/tour-of-csharp/tutorials/branches-and-loops.md	C# if statements and loops - conditional logic tutorial
docs/csharp/tour-of-csharp/tutorials/hello-world.md	Hello World - Introductory tutorial
docs/csharp/tour-of-csharp/tutorials/index.md	Introduction to C#
docs/csharp/tour-of-csharp/tutorials/list-collection.md	Learn to manage data collections using List<T> in C#
docs/csharp/tour-of-csharp/tutorials/numbers-in-csharp.md	docs/csharp/tour-of-csharp/tutorials/numbers-in-csharp
docs/csharp/tour-of-csharp/tutorials/pattern-matching.md	Match data against patterns
docs/csharp/tour-of-csharp/tutorials/tuples-and-types.md	Create types in C#