luafmt over-indents nested tables
Input:

```lua
local a_complex_table = {
  1, 2, {
  'a', 'b', 'c'
}}

add(a({{{{
  1
}}}}))
```

Command: `p8tool luafmt carts/untitled_3.p8 --indentwidth 2`

Expected output: no change

Actual output:

```lua
local a_complex_table = {
  1, 2, {
    'a', 'b', 'c'
  }}

add(a({{{{
            1
          }}}}))
```

Luafmt seems to be indenting to the inner width rather than the outer width, and so is over-spacing tables. This likely applies to non-table nested structures as well.