Add support for Mozilla's Project Fluent localization syntax

[portfiend]

Language

A localization system for natural-sounding translations.

# Simple things are simple.
hello-user = Hello, {$userName}!

# Complex things are possible.
shared-photos =
    {$userName} {$photoCount ->
        [one] added a new photo
       *[other] added {$photoCount} new photos
    } to {$userGender ->
        [male] his stream
        [female] her stream
       *[other] their stream
    }.

Additional resources

• Project Fluent website
• Project Fluent syntax guide
• Fluent on Mozilla Source Docs
• Fluent on Documentation for Mozilla localizers

[Aadityasharma1-programmer]

hey can u assign this issue to mee ? i would love to solve it..