Pretty printing of 1D arrays in rows

[DimitryArefievich]

I admit that this may be against the JSON standard rules, but for me it would be very nice if the AlignmentContext with JSON3.pretty() output can allow me to customize printing out the arrays in rows rather than in columns, i.e., instead of:
"a": [
1,
2,
3
]
it will output:
"a": [ 1, 2, 3 ]

I believe it is sufficient to just remove "\n" in pretty.jl in that choice.