Update GetStarted.md

docs/GetStarted.md

@@ -8,7 +8,7 @@
 
     python pip should also be correctly installed. You could use "which pip" or "pip -V" to check in Linux.
     
-    * Note: For now, we don' support virtual environment.
+    * Note: For now, we don't support virtual environment.
 
 * __Install NNI through pip__