Swift format change to Package.swift (#161)

Co-authored-by: Tao Jia <tjia1818@users.noreply.github.com>

Author: tjia1818

Package.swift

@@ -227,7 +227,7 @@ let package = Package(
                 .copy("Resources/MinimalTokenizer")
             ],
             swiftSettings: [
-                .enableExperimentalFeature("Lifetimes"),
+                .enableExperimentalFeature("Lifetimes")
             ],
             linkerSettings: [
                 .linkedLibrary("c++")