message: docs(pretty-format): fix typos in README
diff: @@ -218,8 +218,8 @@ Write `serialize` to return a string, given the arguments:
  | `min` | `boolean` | minimize added space: no indentation nor line breaks |
  | `plugins` | `array` | plugins to serialize application-specific data types |
  | `printFunctionName` | `boolean` | include or omit the name of a function |
  -| `spacingInner` | `strong` | spacing to separate items in a list |
  -| `spacingOuter` | `strong` | spacing to enclose a list of items |
  +| `spacingInner` | `string` | spacing to separate items in a list |
  +| `spacingOuter` | `string` | spacing to enclose a list of items |
  Each property of `colors` in `config` corresponds to a property of `theme` in `options`:
  