Examples: remove HelloWorld

Remove the `HelloWorld` project.  This was always meant to be closer to
a project template.  This is now deprecated and best handled in an
external repository at
https://github.com/compnerd/swift-win32-application.

The template project provides the appropriate structure without the
additional complexity of a general purpose project.  It should allow for
an easier time for someone to get started.

Author: compnerd

Examples/CMakeLists.txt

@@ -1,3 +1,2 @@
 add_subdirectory(Calculator)
-add_subdirectory(HelloWorld)
-add_subdirectory(UICatalog)
+add_subdirectory(UICatalog)

Examples/HelloWorld/CMakeLists.txt

@@ -9,7 +9,6 @@ let SwiftWin32 = Package(
     .library(name: "SwiftWin32UI", type: .dynamic, targets: ["SwiftWin32UI"]),
     .executable(name: "UICatalog", targets: ["UICatalog"]),
     .executable(name: "Calculator", targets: ["Calculator"]),
-    .executable(name: "HelloWorld", targets: ["HelloWorld"]),
   ],
   dependencies: [
     // NOTE(compnerd) require main as no current release has support for the
@@ -67,22 +66,6 @@ let SwiftWin32 = Package(
         ]),
       ]
     ),
-    .executableTarget(
-      name: "HelloWorld",
-      dependencies: [
-        "SwiftWin32",
-      ],
-      path: "Examples/HelloWorld",
-      exclude: [
-        "CMakeLists.txt",
-        "Info.plist",
-      ],
-      swiftSettings: [
-        .unsafeFlags([
-          "-parse-as-library",
-        ]),
-      ]
-    ),
     .executableTarget(
       name: "UICatalog",
       dependencies: [