[add] percent and permille units

[Ants-Aare]

I removed the unit prefix and currency from #96
Also added accessibility text

[Mc-Zen]

Thank you!

Let me work out and check the Slovenian translation and pluralization.

[Mc-Zen]

Hi @hpcfzl, would you mind looking at the two new definitions for percent and permille regarding the Slovenian translation and the plural forming? I did a bit of research and hope to have generated the correct rules.

[hpcfzl]

Yes, no problem, all added seems correct to me:

• units
• pluralize
• Tests

I have more to share anyway:

• % odstotek is also acceptable as a less common procent anglicism
• ‰ odtisoček is also acceptable as a more common promile anglicism, however since all but the newton so far use the Slovenian translation, I think it's fair to use odtisoček. The least common would be promil, without e, although that's not so simple to determine because ‰ is most commonly used to express concentrations, and those are rarely not floats, where the promile and promil are both promila. The choice of odtisoček also has benefits in the code

Prefixes aren't affected by this, therefore mikroodstotek and mikroodtisoček should be valid. Not that SI would appreciate that.

Why don't we use sym.percent and sym.permille as the keys? We use them elsewhere too.

Otherwise, nicely done to both!

[Mc-Zen]

Thank you very much for the feedback! So do I understand correctly that you deem both choices good?

Why don't we use sym.percent and sym.permille as the keys? We use them elsewhere too.

Good point. Better to be consistent here.

[hpcfzl]

Indeed, I would impose no changes other than the sym.percent and sym.permille keys I mentioned.