app/matrix enable cas proxy for matrix.0x3c.pl

Change-Id: I63c8172dbc93b9f6781aa03f7924be944b8f1846
diff --git a/app/matrix/lib/matrix.libsonnet b/app/matrix/lib/matrix.libsonnet
index 4190941..5f9ecd2 100644
--- a/app/matrix/lib/matrix.libsonnet
+++ b/app/matrix/lib/matrix.libsonnet
@@ -51,6 +51,8 @@
             appserviceTelegram: "dock.mau.dev/tulir/mautrix-telegram@sha256:9e68eaa80c9e4a75d9a09ec92dc4898b12d48390e01efa4de40ce882a6f7e330",
         },
 
+        # Central Authentication Scheme, a single-sign-on system. Note: this flow is now called 'SSO' in Matrix, we keep this name for legacy reasons.
+        # Refer to https://matrix.org/docs/spec/client_server/r0.6.1#sso-client-login
         cas: {
             # whether to enable the CAS proxy (ie. connect to hswaw sso via OAuth)
             enable: false,