docs: update sjson.parse usage

[mikhael-abdallah]

The usage documentation show an out of date usage of the lib. Now the function also receive the "receiver" options.
I suggest to update the doc to:

Checklist

• [ X ] run npm run test and npm run benchmark
• [ X ] tests and/or benchmarks are included
• [ X ] documentation is changed or added
• [ X ] commit message and code follows the Developer's Certification of Origin
  and the Code of conduct

[mcollina]

lgtm