Update README.md

Author: arnaud4d

README.md

@@ -79,6 +79,7 @@ The available properties of `paramObj` are:
 | tenant | text | The {tenant} value in the path of the request can be used to control who can sign into the application. The allowed values are: <ul><li>"common" for both Microsoft accounts and work or school accounts </li><li>"organizations" for work or school accounts only </li><li>"consumers" for Microsoft accounts only</li><li>tenant identifiers such as tenant ID or domain name.</li></ul> Default is "common". |Yes
 | authenticateURI | text | Uri used to do the Authorization request. By default: "https://login.microsoftonline.com/{tenant}/oauth2/v2.0/authorize". |Yes
 | tokenURI | text | Uri used to request an access token. By default: "https://login.microsoftonline.com/{tenant}/oauth2/v2.0/token". |Yes
+|tokenExpiration | text | Timestamp (ISO 8601 UTC) that indicates the expiration time of the token| Yes
 | clientSecret | text | The application secret that you created for your app in the app registration portal. Required for web apps. |Yes
 | token | object | If this property exists, the `getToken()` function uses this token object to calculate which request must be sent. It is automatically updated with the token received by the `getToken()` function.   |Yes
 | timeout|real| Waiting time in seconds (by default 120s).|Yes