Update client/message.go

Co-Authored-By: Luca Moser <moser.luca@gmail.com>

client/message.go

@@ -10,6 +10,8 @@ const (
 	routeFindById = "findById"
 )
 
+// FindMessageById finds messages by the given ids. The messages are returned in the same order as
+// the given ids. Non available messages are empty at their corresponding index.
 func (api *GoShimmerAPI) FindMessageById(base58EncodedIds []string) (*webapi_message.Response, error) {
 	res := &webapi_message.Response{}