Update README.md (#14)

Author: vchrisb

README.md

@@ -115,6 +115,7 @@ jobs:
         api: ${{ secrets.CF_API }}
         client_id: setup-cf
         grant_type: client_credentials
+        jwt: ${{ secrets.JWT }} # can be omitted when using GitHub id token
         org: test
         space: dev
     - name: run cf command
@@ -125,6 +126,8 @@ jobs:
 
 ### Setting up UAA for GitHub Authentication
 
+The GitHub ID token can either be used for JWT Bearer Token Grant or Client Credentials.
+
 #### Prerequisites
 - UAA version 77.20.4 or higher
 - Administrative access to UAA
@@ -251,4 +254,4 @@ npm run build
 
 ## License
 
-This project is licensed under the MIT License - see the LICENSE file for details.
+This project is licensed under the MIT License - see the LICENSE file for details.