Change Language Definitions: Split zh_TW into zh_TW and zh_HK

[wpi3]

Motivation / Problem

There is a considerable amount of difference in terms of vocabulary and grammar between zh_TW and zh_HK. The current translations follows zh_TW standard and ignores zh_HK users, who would find the translations unnatural and too formal, and even uses some vocabulary unique to zh_TW users but not understood by zh_HK users.

There are also some differences in the written forms. By splitting the two, the OS can better choose the correct glyphs to display when the correct language codes are used.

Description

Add a separate txt for zh_HK and change the name and ownname of the traditional_chinese.txt to refer to Taiwan rather than Traditional Chinese.

Limitations

• Changing name and ownname might break stuff with the web translator?
• The grflangid of zh_HK is left blank, as I'm not sure what to fill in there, though it seems arbitary to me

Checklist for review

Some things are not automated, and forgotten often. This list is a reminder for the reviewers.

• The bug fix is important enough to be backported? (label: 'backport requested')
• This PR touches english.txt or translations? Check the guidelines
• This PR affects the save game format? (label 'savegame upgrade')
• This PR affects the GS/AI API? (label 'needs review: Script API')
  • ai_changelog.hpp, gs_changelog.hpp need updating.
  • The compatibility wrappers (compat_*.nut) need updating.
• This PR affects the NewGRF API? (label 'needs review: NewGRF')
  • newgrf_debug_data.h may need updating.
  • PR must be added to API tracker

[frosch123]

I forwarded the request to the translation team. Let's see whether there is interest in maintaining another translation.

[wpi3]

@frosch123 Any updates on this?
Also, to make it clear, I'm native in zh_HK and willing to do the translation.

[frosch123]

@wpi3 There was no reply from the translators on this.

Statistics for zh_TW:

• 4 translators registered.
• 20 outdated strings, 181 missing translations: https://translator.openttd.org/translation/openttd-master/zh_TW
• In december one translator updated 185 translations; this year there have been only 3 changes so far.

So, translation activity is currently not sufficient to keep up with 100% translation status.

Maintaing a translation requires quite some effort, you may you would like to sign up for zh_TW translations first to familarize yourself with the WebTranslator.
Sign-up is here: https://github.com/OpenTTD/team/issues/new/choose