Update README.md

Author: cre8ivepark

README.md

@@ -6,7 +6,7 @@ This repo is where Microsoft's Windows Mixed Reality Design team publishes sampl
 **MRDL is based on [HUX](https://github.com/Microsoft/MRDesignLabs_Unity_Tools) which has an input system that is not compatible with Mixed Reality Toolkit.**
 
 | [Sample app - Lunar Module](https://github.com/Microsoft/MRDesignLabs_Unity_LunarModule) | [Sample app - Periodic Table of the Elements](https://github.com/Microsoft/MRDesignLabs_Unity_PeriodicTable) |
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+|:---------|:--------------|
 |<img src="https://github.com/Microsoft/MRDesignLabs_Unity_LunarModule/blob/master/External/ReadMeImages/LM_hero.jpg" alt="Lunar Module sample app"> | <img src="https://github.com/Microsoft/MRDesignLabs_Unity_PeriodicTable/blob/master/External/ReadMeImages/PeriodicTable_Hero.jpg" alt="Periodic Table of the Elements">|
 |Lunar Module demonstrates how to extend Hololens' base gestures with two hand tracking and xbox controller input, reactive objects to surface mapping and plane finding, and simple menu systems. You can use this project's components to create your own mixed reality app experience. |Periodic Table of the Elements app demonstrates how to use Object Collection to lay out an array of objects in three-dimensional space with various surface types. You can also find the example of using Fluent Design elements such as light, depth, motion and material.|