message: Update readme with ASN example
diff: @@ -16,6 +16,19 @@ Reader.open('/usr/local/share/GeoIP/GeoIP2-City.mmdb').then(reader => {
  console.log(response.country.isoCode) // 'US'
  });
  +```
  +### ASN Example
  +
  +```
  +const reader = require('GeoIP2-node').Reader;
  +
  +Reader.open('/usr/local/share/GeoIP/GeoLite2-ASN.mmdb').then(reader => {
  + const response = reader.asn('128.101.101.101');
  +
  + console.log(response.autonomous_system_number) // 217
  + console.log(response.autonomous_system_organization) // 'University of Minnesota'
  +});
  +
  ```
  ## Copyright and License ##
  