Mutliple languages support

[s0lst1ce]

My feature request is about

• Changing a feature

Description of the solution I'd like
Currently all strings, including messages sent to discord under the form of messages or embeds are in english. This becomes a problem when the members of the said server do not speak this language or just prefer to use their native one.
To prevent language from a being a barrier to using the bot, language file should be made. The bot will thus use variables instead of those strings which will be converted to whichever corresponding string they're supposed to be in their language. This will be done using a new class that will provide all required language files. The language will be per-server and set during initial setup.

Additional context
I (@s0lst1ce) will not maintain them or take any responsibility for them. However if some wish to add their language to it, I will gladly accept their PR. Those should be made directly in the lang folder.
See CONTRIBUTING for more information on this.

What needs to be done

• Add support for other languages
• Add instructions as to how to contribute to the translation

[s0lst1ce]

Ok so I am not pretty sure on how this is going to look. All extensions (and possibly other non-extension files like config or help) will have a a subfolder in lang. Each of these folders will contain a help.en and a strings.en where en will be one of the supported 2 letter language code. The first file will contain the strings help.py will look for when building the help embeds for the commands whereas strings.** will contain the translations for any other string that can be sent by the bot to the users.
As for the structure of the files themselves you'll have something in the kind:

{
	"my_string_name": "my_string_content"
}

and for the help ones:

{
	"command_qualified_name": ["short description", "signature", "long_description"]
}

The strings from strings.** will be accessed like this Translator("en", __name__)["my_string_name"] The parameters are the language and the the qualified name of the extension (ie the name of the file). As this can get tedious it is recommended to define it once at the beginning of each file with a shortcut var (or at the beginning of each command).

[s0lst1ce]

@BlueHolmesMan will make the french translation and will help maintain it as well as #66

[s0lst1ce]

This is now fully fixed! All that's left to do is add the languages.

[s0lst1ce]

Errors can't be translated. This is because they are stored in settings.py. Although it would make less sense we could solve the issue by moving it to utilities.py.

[s0lst1ce]

help and config files do not yet support translation. This is a big problem and although it's going to be easy to adapt config help will be harder since it's passed to the bot instance upon creation.
The language management will have to be done automatically from within and not as a key-word.