Notes for Argentina metadata.

This metadata is heavily processed by code before being exported as XML. This
is because the XML doesn't actually reflect the truth about the Argentinian
phone number plan.

In the Argentinian numbering plan, all phone numbers are 10-digits long,
whereas the XML uses 11-digit numbers to represent mobile ranges (by adding the
dialing prefix 9 to indicate a mobile number). See go/dial-right-number for
some background on this. This applies to "geographic" numbers (those prefixed
by 1, 2 or 3) which are represented in the CSV as fixed-or-mobile and then
processed into two separate ranges.

The aim of this is to keep the CSV data as close to what would be seen in a
numbering plan as possible.
