Support for inline arrays

[Diegovsky]

Currently, toml.lua supports inline tables via a metatable with {inline = true}, but it seems this doesn't apply to arrays, which it could. Here's what I'm talking about:

current_array = [
  "a",
  "b",
  "c",
  "d",
  "e",
  ...
  "z"
]

inlined_array = [ "a", "b", "c", "d", "e", ... "z" ]

The spec does not call them inlined arrays, it just says arrays can span multiple lines or not, but it would be pretty nice if inline applied to arrays too.