Update Week246.md

Issues/Week246.md

@@ -1,6 +1,11 @@
 **Articles**
 
-* 
+* [How drawing works in an Xcode playground](http://iosbrain.com/blog/2018/09/03/how-drawing-works-in-an-xcode-playground/), by [@iosbrain](https://twitter.com/iosbrain)
+* [Early returning functions in Swift](https://www.swiftbysundell.com/posts/early-returning-functions-in-swift), by [@johnsundell](https://twitter.com/johnsundell)
+* [Xcode Source Editor Extension Tutorial: Getting Started](http://www.vadimbulavin.com/xcode-source-editor-extension-tutorial/), by [@V8tr](https://twitter.com/V8tr)
+* [Private properties in protocols](http://alisoftware.github.io/swift/protocols/2018/09/02/protocols-private-properties/), by [@aligatr](https://twitter.com/aligatr)
+* [Enums like never before…](https://agostini.tech/2018/09/02/enums-like-never-before/), by Giuseppe Lanza
+
 
 **Tools/Controls**