Tune the different providers

[am-kantox]

• [x] make the provider changeable in runtime;
• [x] make a pattern for foreign providers to accept language and other params (possibly via protocol);
• [x] map additional parameters to OSM values in OpenStreetMapProvider to support languages etc;
• [ ] make tests for exotic places to make sure all the significant info is properly mapped;
• [x] update a readme to mention different providers.

[am-kantox]

I will provide a pull request for above within one week.

[CyrusNuevoDia]

Sounds good.

If you can submit a pull request sooner that adds your name to the maintainers field in mix.exs (is that enough for you to push to hex?), please do so.

You seem exuberant and motivated enough, not to mention having made / planning to make significant contributions.

[am-kantox]

Thanks. Let me first provide this pull request, it’ll include my name as well. This would be a perfect motivation to complete it sooner :)