configuration in plugin definition

# readme.md
``` javascript
postcss([
  stylefmt
])
```

# question
this doesn't error, but doesn't seem to work. 
my question is, why does this module not accept inline configuration like other modules, and can we add it; may I just be doing something wrong?
``` javascript
postcss([
  stylefmt({'block-opening-brace-newline-before': 'always'})
])
```