Add Santali language under India

Santali is one of the official language of India and is spoken by around 7.5 millions, speakers are also from Nepal, Bangladesh but majority of the population lives in India. It is officially written in Ol Chiki script although before the invention of Ol Chiki script, Santali was written in Devanagari, Bengali, latin and Odia.

The language is active and actively used everywhere ex. Newspaper (Fagun, Online Santali magazine like Birmali.com, Ayorag etc.), News channel (ex. TribeTv) has it's own Wikipedia called Santali Wikipedia (sat.wikipedia.org).

Santali translators are active in Pontoon (Mozilla localisation team known as Santali team), Crowdin.com, and in many other platforms. So, already have experience of doing software translation.

Hence, i request Launchpad team to add Santali language with a rough number reference (https://en.m.wikipedia.org/wiki/Santal_people) under India as Santali people's population is highest in India.

Also, for plural form in Santali language, i have opeaned a bug: https://bugs.launchpad.net/launchpad/+bug/1958693