add json2json (useful to re-gain canonical stations.json format)

#!/usr/bin/env perl

use strict;

use warnings;

use 5.010;

use File::Slurp qw(read_file write_file);

use JSON;

my $json_str = read_file('stations.json');

my $stations = JSON->new->utf8->decode($json_str);

@{$stations} = sort { $a->{name} cmp $b->{name} } @{$stations};

my $json_out = JSON->new->utf8->canonical->pretty->encode($stations);

write_file( 'stations.json', $json_out );