refactor: separate YaMl save() and generic data save

Todos/Controller/SaveController.swift

@@ -13,7 +13,10 @@ final class SaveController {
   }
   
   static func save(_ items: [Project], to: URL) {
-    let data = Data(items.map({ $0.yaml() }).joined().utf8)
+    save(data: Data(items.map({ $0.yaml() }).joined().utf8), to: to)
+  }
+  
+  static func save(data: Data, to: URL) {
     do {
       try data.write(to: to, options: [.atomic, .completeFileProtection])
       let input = try String(contentsOf: to, encoding: .utf8)