Update doc for wp language core install command.

[UmeshSingla]

Related: https://github.com/wp-cli/language-command/issues/90 https://github.com/wp-cli/language-command/issues/90#issuecomment-2148970327 https://github.com/wp-cli/wp-cli/issues/5955

[ernilambar]

Do we have official page with list of all WordPress Locale codes?

https://translate.wordpress.org/ In this page also, it is not clear about Language Code and WordPress Locale code.

[swissspidy]

Why add an additional example for pt_PT that is exactly the same as the wp language core install ja one? 🤔 I don't see the value in providing an example for every locale.

[ernilambar]

@swissspidy Context https://github.com/wp-cli/language-command/issues/90#issuecomment-2148970327

[swissspidy]

OK, thanks I see the context now on the issue.

Instead of adding the same example for multiple locales, it would be better to just explain the expected format, in case that it's unclear.

Do we have official page with list of all WordPress Locale codes? In this page also, it is not clear about Language Code and WordPress Locale code.

It's the grey text below the name:

[UmeshSingla]

@swissspidy

Instead of adding the same example for multiple locales, it would be better to just explain the expected format, in case that it's unclear.

While on it, should I update the existing example with a different language code, which has language code along with the country code in it?

Planning on modifying the text "Language code to install." to "Language code to install, it is based on the ISO-639 language code (e.g. pt for Portuguese) followed by the ISO-3166 country code (e.g. PT for Portugal or BR for Brazil). So, the Brazilian Portuguese file would be called pt_BR" It's just that it's bit too long, hope that isn't an isue?

I've taken that from wordpress.org

I've updated the PR.