message: note about issue with European Co2 intensity data and OS X
diff: @@ -100,7 +100,7 @@ $ unzip f8612019.zip
  4. Download the data from the [European Environment Agency](https://www.eea.europa.eu/data-and-maps/data/approximated-estimates-for-the-share-3/eea-2017-res-share-proxies/2016-res_proxies_eea_csv) and extract the zip file.
  -5. Load utility emissions and identifiers data from the files:
  +5. Load utility emissions and identifiers data from the files. NOTE: There is a [known issue](https://github.com/hyperledger-labs/blockchain-carbon-accounting/issues/76) with loading the European `co2-emissions-intensity` file on Mac OS X, so if you are looking to use this for European data, it will only work on Ubuntu:
  ```bash
  $ node egrid-data-loader.js load_utility_emissions eGRID2018_Data_v2.xlsx NRL18
  