Merge branch 'docs-harishsr-smartcard-active-directory' into 'master'

Document that AD doesn't support Smartcards

See merge request gitlab-org/gitlab!59580

doc/administration/auth/smartcard.md

@@ -108,6 +108,11 @@ attribute. As a prerequisite, you must use an LDAP server that:
 - Supports the `certificateExactMatch` matching rule.
 - Has the certificate stored in the `userCertificate` attribute.
 
+NOTE:
+Active Directory doesn't support the `certificateExactMatch` matching rule so
+[it is not supported at this time](https://gitlab.com/gitlab-org/gitlab/-/issues/327491). For
+more information, see [the relevant issue](https://gitlab.com/gitlab-org/gitlab/-/issues/328074).
+
 ## Configure GitLab for smartcard authentication
 
 **For Omnibus installations**