docs: Improve the description of additionalTrustRoots

Author: siegfriedweber

docs/modules/secret-operator/pages/secretclass.adoc

@@ -133,8 +133,8 @@ spec:
 `additionalTrustRoots.secret`::
     Reference (`name` and `namespace`) to a K8s `Secret` object where the trusted certificates are stored.
     The extension of a key defines its content:
+    * `.crt` denotes a stack of PEM (base64-encoded DER) certificates.
     * `.der` denotes a a binary DER certificates.
-    * `.crt` denotes a stack of base64 encoded DER certificates.
 `autoTls.maxCertificateLifetime`:: Maximum lifetime the created certificates are allowed to have. In case consumers request a longer lifetime than allowed by this setting, the lifetime will be the minimum of both.
 
 [#backend-certmanager]