docs: use settings instead of config in radicale

docs/add-radicale.rst

@@ -24,12 +24,13 @@ have to be used. These can still be generated using `mkpasswd -m bcrypt`.
    in {
      services.radicale = {
        enable = true;
-       config = ''
+       settings = {
-         [auth]
+         auth = {
-         type = htpasswd
+           type = "htpasswd";
-         htpasswd_filename = ${htpasswd}
+           htpasswd_filename = "${htpasswd}";
-         htpasswd_encryption = bcrypt
+           htpasswd_encryption = "bcrypt";
-       '';
+         };
+       };
      };
 
      services.nginx = {