update docs

this cmd fails
```
json -I -f dist/package.json -e this.scripts.start='npm pack'
```
with this error `json: error: lookups cannot be specified with in-place editing (-I/--in-place),`

to make it works just surround the code with extra quotes

```
json -I -f dist/package.json -e "this.scripts.start='npm pack'"
```