Unwrap Japanese characters without inserting space as well

Ref: https://github.com/kaushalmodi/ox-hugo/issues/320

doc/ox-hugo-manual.org

@@ -2846,9 +2846,10 @@ Here's an example of inlining an SVG:
 #+caption: An SVG with hyperlink
 #+attr_html: :inlined t
 [[file:../test/site/content-org/images/svg-with-hyperlinks.svg]]
-*** Chinese Support
+*** CJK Support
 :PROPERTIES:
-:EXPORT_FILE_NAME: chinese-support
+:EXPORT_FILE_NAME: cjk-support
+:EXPORT_HUGO_ALIASES: chinese-support japanese-support
 :END:
 **** Auto-unwrapping of lines with multi-byte characters
 This issue came up on this [[https://emacs-china.org/t/ox-hugo-auto-fill-mode-markdown/9547][emacs-china thread]] .. the issue was that
@@ -2865,10 +2866,11 @@ other languages with multi-byte characters (few examples: Hindi,
 Gujarati).
 
 So that line-unwrapping _with space removal_ is done *only if*,
-1. The /locale/ is [[https://www.gnu.org/software/gettext/manual/html_node/Locale-Environment-Variables.html][auto-detected]] to be Chinese via environment
-   variables /LANGUAGE/, /LC_ALL/ or /LANG/, or
-2. The /locale/ is *manually set* to Chinese by setting it to *zh*
-   using ~#+hugo_locale:~ keyword (or ~EXPORT_HUGO_LOCALE~ property).
+1. The /locale/ is [[https://www.gnu.org/software/gettext/manual/html_node/Locale-Environment-Variables.html][auto-detected]] to be Chinese or Japanese via
+   environment variables /LANGUAGE/, /LC_ALL/ or /LANG/, or
+2. The /locale/ is *manually set* to Chinese or Japanese by setting it
+   to *zh* or *ja* using ~#+hugo_locale:~ keyword (or
+ ~EXPORT_HUGO_LOCALE~ property).
 *** COMMENT Hugo Bundle
 :PROPERTIES:
 :EXPORT_FILE_NAME: hugo-bundle

ox-hugo.el

@@ -1,6 +1,6 @@
 ;;; ox-hugo.el --- Hugo Markdown Back-End for Org Export Engine  -*- lexical-binding: t -*-
 
-;; Authors: Kaushal Modi <kaushal.mod@gmail.com>
+;; Authors: Kaushal Modi <kaushal.modi@gmail.com>
 ;;          Matt Price <moptop99@gmail.com>
 ;; URL: https://ox-hugo.scripter.co
 ;; Package-Requires: ((emacs "24.4") (org "9.0"))
@@ -2466,11 +2466,14 @@ communication channel."
 
     ;; (message "[org-hugo-paragraph DBG] para 1: %s" contents)
 
-    ;; Join consecutive Chinese lines into a single long line without
-    ;; unwanted space inbetween.
-    (let ((lang (org-hugo--get-lang info)))
-      (when (and lang
-                 (string-prefix-p "zh" lang)) ;"zh", "zh_CH", ..
+    ;; Join consecutive Chinese, Japanese lines into a single long
+    ;; line without unwanted space inbetween.
+    (let* ((lang (org-hugo--get-lang info))
+           (lang-2chars (when (and (stringp lang)
+                                   (>= (length lang) 2))
+                          (substring lang 0 2))))
+      (when (and lang-2chars
+                 (member lang-2chars '("zh" "ja"))) ;"zh", "zh_CH", "ja", ..
         ;; https://emacs-china.org/t/ox-hugo-auto-fill-mode-markdown/9547/5
         ;; Example: 这是一个测试     -> 这是一个测试文本 ("This is a test text")
         ;;          文本