Update add-in-authorization-policy-types-in-sharepoint.md (SharePoint#2906)

I have  changed the text to not only concern Project Server 2013 but also Project Online. We are experiencing the noted behavior on Project Online, and we presume it is also an issue for other versions of Project Server - e.g. 2016 and 2019. Specifically, we cannot access the /sites/<pwa>/_api/ProjectData/Resources API nor the /sites/<pwa>/_api/ProjectServer/EnterpriseResources API with app-only principal approach.

Author: Jesper Lund Stocholm

docs/sp-add-ins/add-in-authorization-policy-types-in-sharepoint.md

@@ -22,7 +22,7 @@ SharePoint provides three types of authorization policies:
     An expense approval add-in is an example of an add-in that could be designed to use this policy. The add-in allows users who wouldn't otherwise be able to approve expenses to approve expenses below a certain amount. For an example, see the [scenario](#Scenario) in the next section.
 
     > [!NOTE] 
-    > Certain APIs require a user context and can't be executed with an add-in-only policy. These include many APIs for interacting with Project Server 2013 and for performing search queries.
+    > Certain APIs require a user context and can't be executed with an add-in-only policy. These include many APIs for interacting with Project Server and Project Online and for performing search queries.
 
 - **User-only policy**. When the user-only policy is used, SharePoint checks only the permissions for the user. SharePoint uses this policy when the user is accessing resources directly without using an add-in, such as when a user first opens a SharePoint website's home page or accesses SharePoint APIs from PowerShell.