Consolidate infra artifacts under repo root or eng folder (#647)

Consolidate infra artifacts under repo root or eng folder

Author: MarcoRossignoli

azure-pipelines.yml

@@ -31,9 +31,8 @@ Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Solution Items", "Solution
 	ProjectSection(SolutionItems) = preProject
 		.gitignore = .gitignore
 		eng\azure-pipelines-nightly.yml = eng\azure-pipelines-nightly.yml
-		azure-pipelines.yml = azure-pipelines.yml
-		build.yml = build.yml
-		codecov.yml = codecov.yml
+		eng\azure-pipelines.yml = eng\azure-pipelines.yml
+		eng\build.yml = eng\build.yml
 		Directory.Build.props = Directory.Build.props
 		Directory.Build.targets = Directory.Build.targets
 		global.json = global.json