[Documentation]: Document the command line switch from BuildCheck Stats

[f-alizada]

Summary

There is a functionality of BuildCheck introduced in the PR: https://github.com/dotnet/msbuild/pull/10016 However there is no documentation on the feature and what exactly it could provide.

Proposed Feature

To add documentation to the https://github.com/dotnet/msbuild/blob/main/documentation/specs/proposed/BuildCheck-Architecture.md with the possibilities of the command line switch.