Handling of multi-dimensional arrays

[hhaensel]

Multidimensional arrays are written as flattened arrays.
Is this on purpose, maybe because it's faster?
Other JSON packages use nested arrays.

julia> using JSON

julia> json([1 2 3; 4 5 6])
"[[1,4],[2,5],[3,6]]"

julia> using JSON3

julia> JSON3.write([1 2 3; 4 5 6])
"[1,4,2,5,3,6]"