Update build check documentation

[YuliiaKovalova]

Update build check documentation

[Copilot]

Pull Request Overview

This PR updates the build check documentation to reflect API naming changes from BuildExecutionCheck to Check and BuildExecutionCheckRule to CheckRule. The changes update references and code examples in the documentation files to match the current API.

Key Changes:

• Updated class name references from BuildExecutionCheck to Check in specification and README files
• Updated type references from BuildExecutionCheckRule to CheckRule in code examples
• Updated GitHub links to point to the renamed Check class

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
src/Build/BuildCheck/Infrastructure/EditorConfig/README.md	Updated link reference from BuildExecutionCheck to Check class
documentation/specs/BuildCheck/BuildCheck.md	Updated class names in code examples from BuildExecutionCheck to Check and BuildExecutionCheckRule to CheckRule

[Copilot]

The markdown link syntax is malformed. The URL is nested inside another markdown link syntax, creating an invalid structure.

The current syntax:

[Check]([https://github.com/dotnet/msbuild/blob/main/src/Build/BuildCheck/API/Check.cs](https://github.com/dotnet/msbuild/blob/a73379bc4af3599eb79b899a7c4c56a6c0dff9ff/src/Build/BuildCheck/API/Check.cs#L34))

Should be:

[Check](https://github.com/dotnet/msbuild/blob/a73379bc4af3599eb79b899a7c4c56a6c0dff9ff/src/Build/BuildCheck/API/Check.cs#L34)

Remove the extra brackets and the duplicate URL.

Suggested change

	during the initialization of the [Check]([https://github.com/dotnet/msbuild/blob/main/src/Build/BuildCheck/API/Check.cs](https://github.com/dotnet/msbuild/blob/a73379bc4af3599eb79b899a7c4c56a6c0dff9ff/src/Build/BuildCheck/API/Check.cs#L34)).
	during the initialization of the [Check](https://github.com/dotnet/msbuild/blob/a73379bc4af3599eb79b899a7c4c56a6c0dff9ff/src/Build/BuildCheck/API/Check.cs#L34).

[Copilot]

The word "propogated" is misspelled. It should be "propagated" (with an 'a' in the middle).

Suggested change

	CustomConfigurationData is propogated to the BuildCheck Check instance by passing the instance of [ConfigurationContext](https://github.com/dotnet/msbuild/blob/393c2fea652873416c8a2028810932a4fa94403f/src/Build/BuildCheck/API/ConfigurationContext.cs#L14)
	CustomConfigurationData is propagated to the BuildCheck Check instance by passing the instance of [ConfigurationContext](https://github.com/dotnet/msbuild/blob/393c2fea652873416c8a2028810932a4fa94403f/src/Build/BuildCheck/API/ConfigurationContext.cs#L14)