Add License Field to `package.json` for Clarity and Compatibility

[10xLaCroixDrinker]

I've noticed that while you have a LICENSE file, the license isn't specified in the package.json. I'd like to propose a small yet significant enhancement by adding the license information to your package.json. This change offers several benefits:

• Immediate Visibility: It provides instant clarity regarding the licensing terms right from the package metadata, which is beneficial for users and developers exploring your package.
• Tool Compatibility: Automated tools and services, like npm and GitHub, rely on the package.json file to detect and display license information. This enhancement ensures your project is correctly recognized in various ecosystems.
• Community Best Practices: Including the license in package.json is a common practice in the open-source community. It helps in maintaining consistency with these standards.
• Legal Clarity: Specifying the license in both the package.json and the LICENSE file eliminates ambiguity about your project's licensing terms, which is crucial for legal clarity.

[CLAassistant]

All committers have signed the CLA.

[guybedford]

Sure I'd be happy to add this - note that the next release may be up to a couple of months out yet though as well.