Mention default value for tolerate-time-skewness

example.config.toml

 #
 # Sometimes time can be skewed so we accept all messages within a
 # time range of this parameter.
+#
+# Default value is 3s
 tolerate-time-skewness = "5s"
 
 # Telegram has a concept of DC. You can think about DC as a number of a cluster