Update README.md

Author: huyen-nguyen

README.md

@@ -1,6 +1,6 @@
 # WordStream: An Interactive Tool for Topic Evolution
 
-Demo: https://nnhuyen.github.io/WordStream/
+Demo: https://idatavisualizationlab.github.io/WordStream/
 
 ![ScreenShot](https://github.com/nnhuyen/WordStream/blob/master/images/Huffington.png)
 
@@ -32,4 +32,4 @@ frequency and this current timestep has high frequency.
 
  The metrics includes measurements for the importance of the word displayed. In the process of placing word, some of 
  them are left out due to lack of space. For example, TF-IDF ratio means the rate between the words shown to all the 
- word. 
+ word.