Cannot use priority multiple times

[Martin Ender]

I noticed that the script prevents using one priority multiple times and gives an error

There is already an item with this priority

I haven't used todo.txt CLI but looking at the code it doesn't seem to have such a restriction, and looking at the todotxt.com page the example in their screenshots at the top contain two items with priority (A). Would you consider removing that check?

[E.Z. Hart]

Fixed.