Added welsh (cy)

[IeuanWalker]

#1529

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[IeuanWalker]

Hi, 2 things I'd like to do before changing this draft PR into a complete PR -

• Is there a way to get an output of all the translations being used by the library?
  • I see some languages have custom code to handle their unique differences - https://github.com/Humanizr/Humanizer/tree/main/src/Humanizer/Localisation
  • So I'd like to send an output of what this library would generate to our translation team and they can verify if everything looks ok as is, or if we'd need to look at doing something similar to what other languages have done
• Is there a standard set of tests you expect?
  • Or do you only expect tests if languages have implemented their own code?

[hangy]

* Is there a way to get an output of all the translations being used by the library?
  
  * I see some languages have custom code to handle their unique differences - https://github.com/Humanizr/Humanizer/tree/main/src/Humanizer/Localisation
  * So I'd like to send an output of what this library would generate to our translation team and they can verify if everything looks ok as is, or if we'd need to look at doing something similar to what other languages have done

Not that I know of. Creating all permutations for some languages with support for NumberOfWords, ByteSize, and so on sounds like a lot of information. I wonder if it might be possible to generate that with reflection, though.

* Is there a standard set of tests you expect?
  
  * Or do you only expect tests if languages have implemented their own code?

As far as I've seen, it's good practice to add some tests with new translations. You're correct that it might seem unnecessary if there's no custom code, but since the strings are also run through string.Format or are potentially concatenated in another way, having a test ensures that a change in the base code doesn't break the specific translation.

Do note that I'm just a random contributor and don't speak in any official capacity for the project. :)