Add SPM support

Author: Goos

.gitignore

@@ -7,6 +7,7 @@
 
 ## Build generated
 build/
+.build/
 DerivedData/
 
 ## Various settings

Package.resolved

@@ -0,0 +1,25 @@
+{
+  "object": {
+    "pins": [
+      {
+        "package": "IGListKit",
+        "repositoryURL": "https://github.com/Instagram/IGListKit.git",
+        "state": {
+          "branch": null,
+          "revision": "36da20119ca70c0a8b46ef0acc93b3bcb5a9ea69",
+          "version": "4.0.0"
+        }
+      },
+      {
+        "package": "RxSwift",
+        "repositoryURL": "https://github.com/ReactiveX/RxSwift.git",
+        "state": {
+          "branch": null,
+          "revision": "7c17a6ccca06b5c107cfa4284e634562ddaf5951",
+          "version": "6.2.0"
+        }
+      }
+    ]
+  },
+  "version": 1
+}

Package.swift

@@ -0,0 +1,25 @@
+// swift-tools-version:5.3
+// The swift-tools-version declares the minimum version of Swift required to build this package.
+
+import PackageDescription
+
+let package = Package(
+    name: "RxIGListKit",
+    platforms: [.iOS(.v9)],
+    products: [
+        .library(
+            name: "RxIGListKit",
+            targets: ["RxIGListKit"]),
+    ],
+    dependencies: [
+        .package(url: "https://github.com/ReactiveX/RxSwift.git", from: "6.0.0"),
+        .package(url: "https://github.com/Instagram/IGListKit.git", from: "4.0.0")
+    ],
+    targets: [
+        .target(
+            name: "RxIGListKit",
+            dependencies: ["RxSwift", "IGListKit"],
+            path: "./RxIGListKit"
+        )
+    ]
+)

README.md

@@ -39,6 +39,20 @@ For [Carthage](https://github.com/Carthage/Carthage), add the following to your
 github "RxSwiftCommunity/RxIGListKit" "master"
 ```
 
+For [Swift Package Manager](https://swift.org/package-manager/), add the following to your `Package.swift`
+
+```swift
+dependencies: [
+        .package(url: "https://github.com/RxSwiftCommunity/RxIGListKit.git", branch: "master")
+],
+targets: [
+        .target(
+            name: "MyPackage",
+            dependencies: ["RxIGListKit"]
+        )
+]
+```
+
 ## Author
 
 Bruce-pac, [email protected]