* Rename repos dir to repo-projects
* Move keys dir into prereqs
* Refactor Tools and tools-local dirs
* Refactor ArcadeOverrides dir
* Update .gitignore
* Enable runtime and runtime-portable in source-build known-good.proj
* Add patch that retargets runtime to net7.0
* Re-enable RepositoryReferences to runtime in other repos
* Initial checkin of source-build tarball build infra
* Add a couple more comments
* Update eng/SourceBuild.Version.Details.xml based on PR review
Co-authored-by: Chris Rummel <crummel@microsoft.com>
* Updates based on PR review comments
Co-authored-by: Chris Rummel <crummel@microsoft.com>