Fix incorrect C# compiler option names and broken links in documentation

[Copilot]

This PR addresses several inaccuracies in the C# compiler options documentation that were causing confusion for developers:

Issues Fixed

1. TargetType → OutputType
The documentation incorrectly referenced TargetType as an MSBuild property, but the actual property used in .csproj files is OutputType. Updated all references throughout the documentation to use the correct property name that matches real-world usage:

<!-- Before (incorrect) -->
<TargetType>library</TargetType>

<!-- After (correct) -->
<OutputType>library</OutputType>

2. OutputAssembly Description Clarification
The OutputAssembly section was unclear about which MSBuild properties it actually corresponds to. Updated the description to clarify that it relates to the combination of OutputPath and AssemblyName properties, with corrected examples:

<OutputPath>bin\Debug\</OutputPath>
<AssemblyName>MyApplication</AssemblyName>

3. MainEntryPoint Property Removal
Removed references to the non-existent MainEntryPoint property from the advanced compiler options documentation. This property doesn't exist in MSBuild or Visual Studio, causing confusion when developers tried to use it.

4. StartupObject Flexibility
Fixed the documentation for StartupObject to clarify that fully qualified class names are not always required - simple class names work when unambiguous, making the documentation more accurate and developer-friendly.

5. Broken Link Fixes
Fixed broken anchor links that were created when updating property names. Multiple files had links pointing to the old #targettype anchor that needed to be updated to #outputtype:

• Updated link references in inputs.md and security.md
• Fixed XML property examples to use consistent naming

Cross-Reference Updates

Updated all cross-references across multiple documentation files to ensure consistency, including:

• Error message documentation (CS0734, CS1542, CS1555, etc.)
• F# compiler options documentation
• Framework tools documentation
• Internal cross-references between compiler option pages

These changes ensure the documentation accurately reflects the actual MSBuild property names and behavior that developers encounter when building .NET projects, while also maintaining working internal links.

Fixes #35950.

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Internal previews

Toggle expand/collapse

📄 File	🔗 Preview link
docs/csharp/fundamentals/program-structure/main-command-line.md	Main() and command-line arguments
docs/csharp/fundamentals/program-structure/top-level-statements.md	"Top-level statements - programs without Main methods"
docs/csharp/language-reference/compiler-options/advanced.md	Advanced C# compiler options
docs/csharp/language-reference/compiler-options/inputs.md	"Compiler Options - input file options"
docs/csharp/language-reference/compiler-options/output.md	C# Compiler Options that control compiler output
docs/csharp/language-reference/compiler-options/security.md	docs/csharp/language-reference/compiler-options/security
docs/csharp/misc/cs0017.md	Compiler Error CS0017
docs/csharp/misc/cs0734.md	"Compiler Error CS0734"
docs/csharp/misc/cs1507.md	Compiler Error CS1507
docs/csharp/misc/cs1509.md	docs/csharp/misc/cs1509
docs/csharp/misc/cs1542.md	Compiler Error CS1542
docs/csharp/misc/cs1555.md	"Compiler Error CS1555"
docs/csharp/misc/cs1556.md	Compiler Error CS1556
docs/csharp/misc/cs1557.md	docs/csharp/misc/cs1557
docs/csharp/misc/cs1558.md	Compiler Error CS1558
docs/csharp/misc/cs1559.md	"Compiler Error CS1559"
docs/csharp/misc/cs1927.md	Compiler Warning (Level 2) CS1927
docs/csharp/misc/cs2017.md	docs/csharp/misc/cs2017
docs/csharp/misc/cs2019.md	Compiler Error CS2019
docs/csharp/misc/cs2022.md	"Compiler Error CS2022"
docs/csharp/misc/cs3012.md	Compiler Warning (level 1) CS3012
docs/csharp/misc/cs3013.md	docs/csharp/misc/cs3013
docs/csharp/misc/cs5001.md	Compiler Error CS5001
docs/framework/tools/winmdexp-exe-windows-runtime-metadata-export-tool.md	Winmdexp.exe (Windows Runtime Metadata Export Tool)
docs/fsharp/language-reference/compiler-options.md	Compiler Options

[BillWagner]

@copilot address the review comments

[BillWagner]

@copilot There are several more warnings. Change the following anchors in multiple files:

• "advanced.md#mainentrypoint-or-startupobject" should now be "advanced.md#startupobject"
• "output.md#targettype" should now be "output.md#outputtype"

[Copilot]

@copilot There are several more warnings. Change the following anchors in multiple files:

• "advanced.md#mainentrypoint-or-startupobject" should now be "advanced.md#startupobject"
  ...

Fixed all the broken anchor links as requested. Updated all references from advanced.md#mainentrypoint-or-startupobject to advanced.md#startupobject and from output.md#targettype to output.md#outputtype across 13 files. See commit 41fcab0.

@copilot address the review comments

Addressed the review comments by fixing all broken link warnings. Updated anchor references throughout the documentation to match the corrected property names. See commit 41fcab0.

[BillWagner]

closing and reopening for a fresh build

[BillWagner]

This is ready for final review.