Add benchmark results to readme

[anthonyringoet]

As title states, added benchmark results to readme.

Checklist

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

[mcollina]

Can you please change Bourne.parse to secure-json-parse? thanks

[anthonyringoet]

Yes, that makes sense. Updated the readme and benchmark files.

[RafaelGSS]

@mcollina how periodically will update it?

@anthonyringoet the machine used is a virtualized machine or a desktop/notebook personal with possible external impacts?

[anthonyringoet]

@RafaelGSS Personal notebook. It is certainly not free of possible external impacts as it's not a standardized testing setup. It's always running some other software.

[mcollina]

lgtm