Added material to CoreML section

Author: eleev

README.md

@@ -76,6 +76,7 @@ You may see some non-directly related topics such as `Computer Graphics`, `Machi
 - [Native Machine Learning and Machine Vision in iOS 11](https://hackernoon.com/swift-tutorial-native-machine-learning-and-machine-vision-in-ios-11-11e1e88aa397)
 - [IOS Introduction to Core ML: Building a Simple Image Recognition App](http://www.appcoda.com/coreml-introduction/)
 - [Creating a Simple Game With Core ML in Swift 4](http://www.appcoda.com/coreml-game/)
+- [A Beginner’s Guide to Core ML Tools: Converting a Caffe Model to Core ML Format](http://www.appcoda.com/core-ml-tools-conversion/)
 
 ## SceneKit
 - [Physically Based Rendering Using the New iOS 10 SceneKit](https://medium.com/@avihay/amazing-physically-based-rendering-using-the-new-ios-10-scenekit-2489e43f7021)