Request to add license to repo

[goneall]

Greetings - I noticed that the package.json file states a license of MIT, yet no license file was found in the repository. To make it clearer and easier for the downstream users to identify the license, would you mind adding an MIT license (https://opensource.org/licenses/MIT) to the source tree? Let me know if you would like me to make a pull request with the license text.

Thanks,
Gary