deterministic flag

[lsnow99]

Example output:

#########################################################################################
#                                                                                       #
# This script was auto-generated from a Justfile by just.sh.                            #
#                                                                                       #
# Generated with just.sh version 0.0.2.                                                 #
# https://github.com/jstrieb/just.sh                                                    #
#                                                                                       #
# Run `./just.sh --dump` to recover the original Justfile.                              #
#                                                                                       #
#########################################################################################

I did not write a test, but am happy to if requested

[jstrieb]

Needs a test of the new flag to get to 100% line coverage. Then I will merge.