Fix up the README table layout issue.

The previous change added some new information into the middle table, which broke the table formatting (table content must be contiguous otherwise it ends up just rendering the | and ---- values as-is)

Author: wiwei

README.md

@@ -74,6 +74,8 @@ For more information see the [Code of Conduct FAQ](https://opensource.microsoft.
 
 # Useful resources on Microsoft Windows Dev Center
 | ![Academy](External/ReadMeImages/icon_academy.png) [Academy](https://developer.microsoft.com/en-us/windows/mixed-reality/academy)| ![Design](External/ReadMeImages/icon_design.png) [Design](https://developer.microsoft.com/en-us/windows/mixed-reality/design)| ![Development](External/ReadMeImages/icon_development.png) [Development](https://developer.microsoft.com/en-us/windows/mixed-reality/development)| ![Community)](External/ReadMeImages/icon_community.png) [Community](https://developer.microsoft.com/en-us/windows/mixed-reality/community)|
+| :--------------------- | :----------------- | :------------------ | :------------------------ |
+| See code examples. Do a coding tutorial. Watch guest lectures.          | Get design guides. Build user interface. Learn interactions and input.     | Get development guides. Learn the technology. Understand the science.       | Join open source projects. Ask questions on forums. Attend events and meetups. |
 
 ### For details on the different branches used in the Mixed Reality Toolkit repositories, check this [Branch Guide here](https://github.com/Microsoft/MixedRealityToolkit-Unity/wiki/Branch-Guide).
 
@@ -83,8 +85,5 @@ For more information see the [Code of Conduct FAQ](https://opensource.microsoft.
 
 > Learn more about the approach behind the [Windows Mixed Reality - vNext SDK](/MRTK-SDK.md) here.
 
-| :--------------------- | :----------------- | :------------------ | :------------------------ |
-| See code examples. Do a coding tutorial. Watch guest lectures.          | Get design guides. Build user interface. Learn interactions and input.     | Get development guides. Learn the technology. Understand the science.       | Join open source projects. Ask questions on forums. Attend events and meetups. |
-
 # How to Contribute
 View the [**How To Contribute**](https://github.com/Microsoft/MixedRealityToolkit-Unity/wiki/How-to-Contribute) wiki page for the most up to date instructions on contributing to the Mixed Reality Toolkit!