Key names to match ISO

[goodeye]

Thank you for this handy reference for the ISO countries. I ran into conflict with the key names not matching ISO's key names. ISO uses Alpha-2, Alpha-3, Numeric in displays and discussions. In their CSV sample files, the headings are alpha_2_code, alpha_3_code, numeric_code.
It would be a breaking change to rename them, but I just wanted to note it. It came up when doing the variable names in our project.
(We're going with Alpha2, Alpha3, Numeric; translating from your files; and avoiding ISO's kebab-case.)

Somewhat related to the hyphen question #27