Remove Autoprefixer from “Built with rework”

It isn’t.
Merge pull request #162 from lydell/update-readme

Remove Autoprefixer from “Built with rework”
fix link
Merge pull request #165 from yuanchuan/update-readme

fix link
Minor README updates
Depend on 'css' 2.0.0

Update the expected test results to match changes to the source maps
feature of the 'css' package.
Remove unused 'component' devDependency
Don't set `options.position = true` in `rework()`

That option has been removed from `css.parse()`.
Update readme

- Sync it with the reworkcss/css readme.
- Put the "Built with rework" section last.
- Remove the "descriptions" of the "Built with rework" entries.
- Explicitly say that `options` are passed to `css`.
- Document the `sourcemapAsObject` option.
- Minor whitespace and punctuation fixes.