Add note that domain-manager test currently requires user account (#1121)

Signed-off-by: Felix Kronlage-Dammers <fkr@hazardous.org>

Author: fkr

Standards/scs-0302-v1-domain-manager-role.md

@@ -161,6 +161,8 @@ There is a test suite in [`domain-manager-check.py`](https://github.com/Sovereig
 The test suite connects to the OpenStack API using two sample domains and corresponding Domain Manager accounts.
 It verifies the compliance to the standard and the proper domain-scoping as defined by the Keystone policy.
 Please consult the associated [README.md](https://github.com/SovereignCloudStack/standards/blob/main/Tests/iam/domain-manager/README.md) for detailed setup and testing instructions.
+The test suite, [`domain-manager-check.py`](https://github.com/SovereignCloudStack/standards/blob/main/Tests/iam/domain-manager/domain-manager-check.py),
+does not currently work with application credentials, authentication with username and password is required.
 
 ## Appendix