Add xx-messenger example

Examples/Package.swift

...er/.swiftpm/xcode/xcshareddata/xcschemes/AppCore.xcscheme

....swiftpm/xcode/xcshareddata/xcschemes/AppFeature.xcscheme

...swiftpm/xcode/xcshareddata/xcschemes/HomeFeature.xcscheme

...iftpm/xcode/xcshareddata/xcschemes/LaunchFeature.xcscheme

...tpm/xcode/xcshareddata/xcschemes/RegisterFeature.xcscheme

...ftpm/xcode/xcshareddata/xcschemes/RestoreFeature.xcscheme

...ftpm/xcode/xcshareddata/xcschemes/WelcomeFeature.xcscheme

Examples/xx-messenger/LICENSE

Examples/xx-messenger/Package.swift

Examples/xx-messenger/Project/Package.swift

...x-messenger/Project/XXMessenger.xcodeproj/project.pbxproj

...er.xcodeproj/project.xcworkspace/contents.xcworkspacedata

...project.xcworkspace/xcshareddata/IDEWorkspaceChecks.plist

...ger.xcodeproj/xcshareddata/xcschemes/XXMessenger.xcscheme

...senger/Assets.xcassets/AccentColor.colorset/Contents.json

...essenger/Assets.xcassets/AppIcon.appiconset/Contents.json

...s.xcassets/AppIcon.appiconset/iOS App Store 1024pt 1x.png

...r/Assets.xcassets/AppIcon.appiconset/iPad App 76pt 1x.png

...r/Assets.xcassets/AppIcon.appiconset/iPad App 76pt 2x.png