Add GitHub update checker and installer

Library/Update/UpdateInfo.swift

@@ -0,0 +1,26 @@
+import Foundation
+
+public struct UpdateInfo: Codable {
+    public let versionName: String
+    public let releaseURL: String
+    public let downloadURL: String
+    public let releaseNotes: String?
+    public let isPrerelease: Bool
+    public let fileSize: Int64
+
+    public init(
+        versionName: String,
+        releaseURL: String,
+        downloadURL: String,
+        releaseNotes: String?,
+        isPrerelease: Bool,
+        fileSize: Int64
+    ) {
+        self.versionName = versionName
+        self.releaseURL = releaseURL
+        self.downloadURL = downloadURL
+        self.releaseNotes = releaseNotes
+        self.isPrerelease = isPrerelease
+        self.fileSize = fileSize
+    }
+}