Updated Swift tools version and added missing requirements

Author: bellebethcooper

Package.swift

@@ -1,5 +1,20 @@
+// 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: "TableKit"
-)
+    name: "TableKit",
+
+    products: [
+        .library(
+            name: "TableKit",
+            targets: ["TableKit"]),
+    ],
+
+    targets: [
+        .target(
+            name: "TableKit",
+            path: "Sources")
+    ]
+)