CLI

[rkh]

I've been thinking about adding a CLI.

Features I can envision:

• Sync messages between two locales (ie, copy all existing message keys with comments from English to another language).
• Convert a file or directory to Fluent.
• List translations, find missing translations, etc.
• Import/Export XLIFF (which would make it easier to have an external agency do the translations). Possibly also to gettext/po, but I don't think that can be done without losing information.

Biggest challenge I see is loading the appropriate configuration (or maybe we don't want to do this, as that might lead down a rabbit whole where we might have to load the entire application).