Before:
  let &gdefault = 1

After:
  let &gdefault = 0

Given markdown;
| normal |no space|  2 spaces  ||
| - |-|  --- ||
| normal |no space|  2 spaces  ||

Execute (format unformatted table):
  TableFormat

Expect (table is formatted):
  | normal | no space | 2 spaces |  |
  |--------|----------|----------|--|
  | normal | no space | 2 spaces |  |

Given markdown;
| a | b |
|---|---|
| c | d |

Execute (format well formatted table):
  TableFormat

Expect (table is not modified):
  | a | b |
  |---|---|
  | c | d |

Given markdown;
| left |right|  center  ||
| :- | --: |:---:|:|
| left |right|  center  ||

Execute (format table with colons):
  TableFormat

Expect (preserve colons to align text):
  | left | right | center |   |
  |:-----|------:|:------:|:--|
  | left | right | center |   |
