usage should be updated

[loynoir]

Example in readme

A library available for browser, also provide cli.
When using bundler,

import esMain from 'es-main';

// library code

if (esMain(import.meta)) {
  // cli only code
}

Expected

// library code

Actual

// es-main source code

// library code

if (esMain(import.meta)) {
  // cli only code
}

Pull

#15

[Tim Schaub]

I guess this should have been closed when #15 was closed.