Reinstate supplemental remarks (System.D*)

[gewarren]

Contributes to #12613.

Also removes .NET Framework remarks.

[Copilot]

Pull request overview

This PR reintegrates “supplemental API remarks” content back into this repo for several System.D* APIs (per dotnet-api-docs#12613) by replacing external links with in-file markdown remarks, and adds/updates snippet projects to support the restored documentation content.

Changes:

• Replaced “Supplemental API remarks” link-only <remarks> with restored markdown remarks in multiple xml/ API reference files.
• Added new C# and Visual Basic snippet source files and SDK-style snippet projects to support the new remarks content.
• Updated the EventSource snippet project target framework to net10.0 and adjusted snippet sources accordingly.

Reviewed changes

Copilot reviewed 40 out of 42 changed files in this pull request and generated 7 comments.

Show a summary per file

File	Description
xml/System.Dynamic/ExpandoObject.xml	Replaces link-only remarks with restored markdown remarks and snippet includes.
xml/System.Drawing.Drawing2D/Matrix.xml	Replaces link-only remarks with restored markdown remarks, images, and snippet includes.
xml/System.Diagnostics/ProcessStartInfo.xml	Restores markdown remarks for UseShellExecute.
xml/System.Diagnostics/PerformanceCounterType.xml	Restores extensive markdown remarks and example snippet includes.
xml/System.Diagnostics.Tracing/EventWrittenEventArgs.xml	Restores markdown remarks explaining key properties and runtime behavior.
xml/System.Diagnostics.Tracing/EventSource.xml	Restores detailed markdown remarks plus snippet references for examples/advanced usage.
xml/System.Data/DataTable.xml	Restores markdown remarks plus an added example snippet reference.
xml/System.Data/DataSet.xml	Restores markdown remarks describing usage patterns and behavior.
xml/System.Data/DataColumn.xml	Restores detailed markdown remarks for Expression syntax and examples.
xml/System.Data/CommandBehavior.xml	Restores markdown remarks describing usage notes and caveats.
snippets/visualbasic/System.Dynamic/ExpandoObject/Overview/Project.vbproj	Adds VB snippet project for ExpandoObject overview snippets.
snippets/visualbasic/System.Dynamic/ExpandoObject/Overview/module1.vb	Adds VB snippet implementations for ExpandoObject remarks sections.
snippets/visualbasic/System.Drawing.Drawing2D/Matrix/Overview/Project.vbproj	Adds VB WinForms snippet project for Matrix examples.
snippets/visualbasic/System.Drawing.Drawing2D/Matrix/Overview/Class1.vb	Adds VB Matrix example code with snippet regions.
snippets/visualbasic/System.Diagnostics/PerformanceCounterType/Overview/rawfraction.vb	Adds VB PerformanceCounterType example snippet (RawFraction).
snippets/visualbasic/System.Diagnostics/PerformanceCounterType/Overview/rateofcountspersecond64.vb	Adds VB PerformanceCounterType example snippet (RateOfCountsPerSecond64).
snippets/visualbasic/System.Diagnostics/PerformanceCounterType/Overview/rateofcountspersecond32.vb	Adds VB PerformanceCounterType example snippet (RateOfCountsPerSecond32).
snippets/visualbasic/System.Diagnostics/PerformanceCounterType/Overview/Project.vbproj	Adds VB snippet project for PerformanceCounterType examples (+ package ref).
snippets/visualbasic/System.Diagnostics/PerformanceCounterType/Overview/program.vb	Adds VB PerformanceCounterType example snippet (SampleFraction).
snippets/visualbasic/System.Diagnostics/PerformanceCounterType/Overview/numberofitems64.vb	Adds VB PerformanceCounterType example snippet (NumberOfItems64).
snippets/visualbasic/System.Diagnostics/PerformanceCounterType/Overview/numberofitems32.vb	Adds VB PerformanceCounterType example snippet (NumberOfItems32).
snippets/visualbasic/System.Diagnostics/PerformanceCounterType/Overview/elapsedtime.vb	Adds VB PerformanceCounterType example snippet (ElapsedTime).
snippets/visualbasic/System.Diagnostics/PerformanceCounterType/Overview/averagetimer32.vb	Adds VB PerformanceCounterType example snippet (AverageTimer32).
snippets/visualbasic/System.Diagnostics/PerformanceCounterType/Overview/averagecount32.vb	Adds VB PerformanceCounterType example snippet (AverageCount64).
snippets/visualbasic/System.Diagnostics.Tracing/EventSource/Overview/Project.vbproj	Adds VB snippet project for EventSource examples.
snippets/visualbasic/System.Diagnostics.Tracing/EventSource/Overview/program1.vb	Adds VB EventSource example snippet (richer example).
snippets/visualbasic/System.Diagnostics.Tracing/EventSource/Overview/program.vb	Adds VB EventSource example snippet (simple example).
snippets/csharp/System.Diagnostics/PerformanceCounterType/Overview/rawfraction.cs	Adds C# PerformanceCounterType example snippet (RawFraction).
snippets/csharp/System.Diagnostics/PerformanceCounterType/Overview/rateofcountspersecond64.cs	Adds C# PerformanceCounterType example snippet (RateOfCountsPerSecond64).
snippets/csharp/System.Diagnostics/PerformanceCounterType/Overview/rateofcountspersecond32.cs	Adds C# PerformanceCounterType example snippet (RateOfCountsPerSecond32).
snippets/csharp/System.Diagnostics/PerformanceCounterType/Overview/Project.csproj	Adds C# snippet project for PerformanceCounterType examples (+ package ref).
snippets/csharp/System.Diagnostics/PerformanceCounterType/Overview/program.cs	Adds C# PerformanceCounterType example snippet (SampleFraction).
snippets/csharp/System.Diagnostics/PerformanceCounterType/Overview/numberofitems64.cs	Adds C# PerformanceCounterType example snippet (NumberOfItems64).
snippets/csharp/System.Diagnostics/PerformanceCounterType/Overview/numberofitems32.cs	Adds C# PerformanceCounterType example snippet (NumberOfItems32).
snippets/csharp/System.Diagnostics/PerformanceCounterType/Overview/averagetimer32.cs	Adds C# PerformanceCounterType example snippet (AverageTimer32).
snippets/csharp/System.Diagnostics.Tracing/EventSource/Overview/program2.cs	Adds C# EventSource advanced examples (interfaces/utility source/complex source).
snippets/csharp/System.Diagnostics.Tracing/EventSource/Overview/program.cs	Adjusts namespace to avoid type collisions within the sample project.
snippets/csharp/System.Diagnostics.Tracing/EventSource/Overview/etwtracesmall.csproj	Updates sample project to target net10.0.
snippets/csharp/System.Data/DataTable/Overview/source.cs	Adds a new C# DataTable example snippet used by restored remarks.
snippets/csharp/System.Data/DataTable/Overview/project.csproj	Adds a new C# snippet project for the DataTable example.