remove codepen

Author: nicolocarpignoli

docs/index.md

@@ -118,7 +118,7 @@ Here we present three, basic examples, one for each AR feature. For specific doc
 
 Please follow these simple steps:
 
-- Create a new project with the code below (or [**try this codepen**](https://codepen.io/nicolocarpignoli/pen/vYOeYKd) and go directly to the last step)
+- Create a new project with the code below (or [open this live example](https://ar-js-org.github.io/AR.js/aframe/examples/image-tracking/nft/) and go directly to the last step)
 - Run it on a server
 - Open the website on your phone
 - Scan [this picture](https://raw.githack.com/AR-js-org/AR.js/master/aframe/examples/image-tracking/nft/trex-image-big.jpeg) to see content through the camera.
@@ -224,7 +224,7 @@ Please follow these simple steps:
 
 Please follow these simple steps:
 
-- Create a new project with the code below (or [**try this codepen**](https://codepen.io/nicolocarpignoli/pen/vMBgob) and go directly to the last step)
+- Create a new project with the code below (or [open this live example](https://ar-js-org.github.io/AR.js/aframe/examples/marker-based/basic.html) and go directly to the last step)
 - Run it on a server
 - Open the website on your phone
 - Scan [this picture](https://raw.githubusercontent.com/AR-js-org/AR.js/master/data/images/hiro.png) to see content through the camera.