cli example command doesn't work

When I run:
```
➜  storybooks-github-io git:(source) ✗ ./node_modules/.bin/remark -u lint -u lint-code="{\"js\":\"remark-lint-code-eslint\"}" .
Error: Cannot parse `{"js":"remark-lint-code-eslint"}` as JSON: Unexpected token { in JSON around position 1
```
This is the example giving in the readme, so this would appear broken.