Exclude SWBWindowsPlatform/README in manifest

Author: owenv

Package.swift

@@ -262,7 +262,7 @@ let package = Package(
         .target(
             name: "SWBWindowsPlatform",
             dependencies: ["SWBCore", "SWBMacro", "SWBUtil"],
-            exclude: ["CMakeLists.txt"],
+            exclude: ["CMakeLists.txt", "README.md"],
             resources: [.process("Specs")],
             swiftSettings: swiftSettings(languageMode: .v6)),