Add package.swift

Author: wu-hui

Package.swift

@@ -0,0 +1,23 @@
+// swift-tools-version:5.0
+// The swift-tools-version declares the minimum version of Swift required to build this package.
+import PackageDescription
+
+let package = Package(
+  name: "nlohmann_json",
+  products: [
+    .library(
+      name: "nlohmann_json",
+      targets: ["nlohmann_json"]
+    )
+  ],
+
+  targets: [
+    .target(
+      name: "nanopb",
+      path: ".",
+      sources: [
+      ],
+      publicHeadersPath: "single_include",
+    ),
+  ]
+)