First and last entries in problem 07

[aral]

It might be worth mentioning that the genesis entry should not be written to the file or stored in the log (otherwise, if it is removed, the reduce function will start with the new 1st entry in the accumulator and the 2nd entry in the current and the first entries details can be modified without detection).

Also, as we’re not saving the hash of the whole log, entries can be deleted from the end without detection.

Is it worth addressing these in the text?