README update needed for CommonJS usage in v4.0.1

[michaelcais]

Hi, and thank you for maintaining this package!

After updating from v3.0.1 to v4.0.1, I received the error get is not a function and noticed that the package now uses an ES module default export. When using CommonJS with require, the default export must be accessed via the .default property:

const get = require('get-value').default;

The README still shows the previous CommonJS usage:

const get = require('get-value');

It would be helpful if the README could be updated to reflect this change for CommonJS users using the latest package. Thanks for considering!