remove caveat about impersonation

Impersonation is supported now. No update is necessary.

refs #39

Author: cmatheson

README.md

@@ -116,7 +116,3 @@ The following claims may be populated if the user is part of an organization:
 - `organizationId`: The currently-selected organization.
 - `role`: The `role` of the user for the current organization.
 - `permissions`: Permissions corresponding to this role.
-
-## Impersonation
-
-Impersonation is not currently supported in authkit-js but is on the roadmap for 2024.