Update docs/configuring-playbook-ldap-auth.md: unrecommend using ma1sd for authentication

Signed-off-by: Suguru Hirahara <acioustick@noreply.codeberg.org>

docs/configuring-playbook-ldap-auth.md

@@ -29,9 +29,11 @@ If you wish for users to **authenticate only against configured password provide
 matrix_synapse_password_config_localdb_enabled: false
 ```
 
-## Using ma1sd Identity Server for authentication
+## Using ma1sd Identity Server for authentication (not recommended)
 
-If you wish to use the ma1sd Identity Server for LDAP authentication instead of [matrix-synapse-ldap3](https://github.com/matrix-org/matrix-synapse-ldap3) consult [Adjusting ma1sd Identity Server configuration](configuring-playbook-ma1sd.md#authentication).
+The playbook can instead configure [ma1sd](https://github.com/ma1uta/ma1sd) Identity Server for LDAP authentication. However, **we recommend not bothering with installing it** as ma1sd has been unmaintained for years.
+
+If you wish to install it anyway, consult the [ma1sd Identity Server configuration](configuring-playbook-ma1sd.md#authentication).
 
 ## Handling user registration