Add Utilities/README.md

Author: bkhouri

Utilities/README.md

@@ -0,0 +1,11 @@
+# Windows Self-Hosted Test
+
+Steps to be confirmed
+
+```
+${REPO_ROOT_PATH} = git rev-parse --show-toplevel
+${TARGET_PATH} = "C:\source"
+
+docker pull swiftlang/swift:nightly-main-windowsservercore-1809
+docker run --rm --volume "${REPO_ROOT_PATH}:${TARGET_PATH}" --interactive --tty --name "win_test" --workdir "${TARGET_PATH}" swiftlang/swift:nightly-main-windowsservercore-1809 python3 .\Utilities\build-using-self
+```