Add a license

[Hugo Locurcio]

The package.json hints at this project being licensed under the ISC license, but since it is the default choice set by npm init, it may have limited legal value.

Please consider adding an open source license; see Choose a License for more informtaion. Thanks in advance 😃

[Tamás Koczka]

Yeah, sorry, I forgot to add one, I will add MIT license in an hour.

[Hugo Locurcio]

Thanks! Can you also change the license field to MIT in package.json, please?

[Tamás Koczka]

Done. (note: changed other fields too)