Add support for Lua input

[Zash]

The missing input half of #1700 / #1745

Uses a full blown Lua parser, it will happily while true do --[[ nothing, forever ]] end so best keep away from untrusted input. Be on the lookout for a way to limit this or a more limited parser. 😅

Given a sample.lua file of:

return {
        ["country"] = "Australia"; -- this place
        ["cities"] = {
                "Sydney",
                "Melbourne",
                "Brisbane",
                "Perth",
        };
};

then

yq -oy '.' sample.lua

will output

country: Australia
cities:
  - Sydney
  - Melbourne
  - Brisbane
  - Perth

[mikefarah]

Brilliant