[Feature Request] Localizations

### Whats purpose of that?
First of all to make bot understandable for even more wide auditory.

### How I see this would be realized?
There is two variants of this feature

1. Make prebuilt locales that will switch in main config, like `language=en_EN`
2. Make external file with messages which could be translated or adapted to any server purposes, like:
`songAddedToQueue="Song %songname% %duration% added to queue"`

p.s. Thank you for this project, from the people for the people

No files, tests, or entry points are named. Start by locating the bot's user-facing messages and main configuration, then determine how locale selection or external message files would fit; the work is complete when one supported locale and the proposed customizable message format work consistently across the bot.

Written by the indexing model from the issue text.