Add support for maps and lists

[lazopm]

It would be great if this was supported. How hard would it be to add basic support?

in:
$list: (1, 2, 3);
out:
{list: [1, 2, 3]}

in:

$map: (
    hello: 1,
    world: 2
);

out:
{map: { hello: 1, world: 3 }}

[JohnLindahlTech]

Since we are reading line by line currently the first example with list should be possible to implement but the second one with map and multiline could be a bit more hairy. Since it also is a quite similar syntax as normal varaibles.

That said, sadly I am quite bogged down with other work so I will not have the time to implement this currently myself since we are not using this functionallity currently. I would gladly accept a PR with tests to prove it working.

[Billy-]

I'll have a go at implementing this

[Billy-]

I have used the above fork and published to my private registry - it enables basic support for maps, should anyone need it.