Update DocC plugin (#15)

Author: hiroshihorie

Package.swift

@@ -18,7 +18,7 @@ let package = Package(
     ],
     dependencies: [
         .package(url: "https://github.com/livekit/client-sdk-swift.git", from: "2.0.14"),
-        .package(url: "https://github.com/apple/swift-docc-plugin.git", from: "1.3.0"),
+        .package(url: "https://github.com/apple/swift-docc-plugin.git", from: "1.4.3"),
     ],
     targets: [
         .target(