Update README.md

Change branch from "master" to "Main"

Author: cgallred

README.md

@@ -2,7 +2,7 @@
 
 |Branch|Functional Tests|
 |:--:|:--:|
-|**master**|[![Build status](https://dev.azure.com/projfs/ci/_apis/build/status/PR%20-%20Build%20and%20Functional%20Test%20-%202019?branchName=master)](https://dev.azure.com/projfs/ci/_build/latest?definitionId=5)|
+|**main**|[![Build status](https://dev.azure.com/projfs/ci/_apis/build/status/PR%20-%20Build%20and%20Functional%20Test%20-%202019?branchName=main)](https://dev.azure.com/projfs/ci/_build/latest?definitionId=5)|
 |**release**|[![Build status](https://dev.azure.com/microsoft/OS/_apis/build/status/ProjFS%20CI%20-%20Build,%20Sign,%20Package)](https://dev.azure.com/microsoft/OS/_build/latest?definitionId=37476)|
 
 ## About ProjFS