Example for services.syncthing.declarative.devices is incorrect

[danielfullmer]

Issue description

The new option services.syncthing.declarative.devices has the example:

          example = [
            {
              name = "bigbox";
              id = "7CFNTQM-IMTJBHJ-3UWRDIU-ZGQJFR6-VCXZ3NB-XUH3KZO-N52ITXR-LAIYUAU";
              addresses = [ "tcp://192.168.0.10:51820" ];
            }
          ];

This is a list of attrsets, but this doesn't match the type, which is types.attrsOf (types.submodule ...

Also, it would be nice to have an example config for services.syncthing.declarative.folders as well.

Besides this, the new declarative configuration options for syncthing have been working well for me. Thanks for including them.

CC @Lassulus