Create a seed locale in CLDR

This language is lacking an entry in the Common Locale Data Repository (CLDR). The core
data used for creating a seed locale should ideally be submitted to the [CLDR trac](https://unicode.org/cldr/trac/)
before the 1st April, 2018.

You can use the [ticket about Tuvan](https://unicode.org/cldr/trac/ticket/10985) as a template.

Note that if a two-letter code is available (e.g. `av` for Avar) then it should be used instead of the three-letter code.

The process is as follows:

* Provide the characters in the '''Exemplar sets'''
* Provide the singular and plural forms (for Turkic only two matter)
* Check the [territory information](https://www.unicode.org/cldr/charts/latest/supplemental/language_territory_information.html) and copy the relevant lines
* Provide a character--character transliteration scheme (it doesn't have to be perfect).

In addition you can provide a seed locale file based on the [Chuvash example](http://unicode.org/repos/cldr/trunk/seed/main/cv.xml).