refactor: migrate i18n files from YAML to TOML format and simplify structure (#1230)

* refactor: migrate i18n files from YAML to TOML format and simplify structure

* refactor: make translation file adjust to gohugoio/locales language code so date translation can work properly

* refactor: use hyphens instead of underscores for i18n, because that's how Hugo pick the translation file

* docs: update comments for i18n language availability and CJK language detection in hugo.toml.

demo/config/_default/hugo.toml

@@ -4,17 +4,16 @@ title        = "Example Site"
 copyright    = "Example Person"
 
 # Theme i18n support
-# Available values: ar, bn, ca, de, el, en, es, fr, hu, id, it, ja, ko, nl, pt-br, th, uk, zh-cn, zh-hk, zh-tw
+# See i18n folder for available languages
 defaultContentLanguage = "en"
 
-# Set hasCJKLanguage to true if DefaultContentLanguage is in [zh-cn ja ko]
-# This will make .Summary and .WordCount behave correctly for CJK languages.
+# Set hasCJKLanguage to true if DefaultContentLanguage is a CJK language
+# This will make .Summary and .WordCount behave correctly
 hasCJKLanguage = false
 
 [[module.imports]]
 path = "github.com/CaiJimmy/hugo-theme-stack/v3"
 
-
 [pagination]
     pagerSize = 3
 

demo/config/_default/languages.toml

@@ -5,18 +5,18 @@
     [en.params.sidebar]
         subtitle = "Example description"
 
-[zh-cn]
+[zh]
     languageName = "简体中文"
     title        = "演示站点"
     weight       = 2
-    [zh-cn.params.sidebar]
+    [zh.params.sidebar]
         subtitle = "演示说明"
 
-[zh-tw]
+[zh-hant-tw]
     languageName = "正體中文"
     title        = "演示站點"
     weight       = 2
-    [zh-tw.params.sidebar]
+    [zh-hant-tw.params.sidebar]
         subtitle = "演示說明"
 
 [ja]

demo/config/_default/params.toml

@@ -5,10 +5,6 @@ favicon        = ""
 [footer]
     since = 2020
 
-[dateFormat]
-    published   = "Jan 02, 2006"
-    lastUpdated = "Jan 02, 2006 15:04 MST"
-
 [sidebar]
     emoji    = "🍥"
     subtitle = "Lorem ipsum dolor sit amet, consectetur adipiscing elit."