Add Japanese (Katakana, Hiragana)

[lart-rt]

Added “map” and “post” files for Katakana and Hiragana in Japanese.

First, we created the files for Katakana. And then, we produced the files for Hiragana by replacing Katakana in the previous files with Hiragana because the two writing systems are in one-to-one correspondence.

The files without the suffix “-red” are based on the descriptions in the following literature about linguistics and phonetics of Japanese:

• Nihongo Kyoiku Gakkai ed. Encyclopedia of Japanese Language Education (new edition (Taishukan Shoten, 2005, in Japanese)
• Yoshio Saito Introduction to Japanese Phonetics (revised) (Sanseido, 2006, in Japanese)

The files with “-red” are more “reduced” version based on the description in the following articles in Wikipedia.

• Katakana (Aug. 9, 2022, 08:15 UTC). In Wikipedia: The Free Encyclopedia. Retrieved from https://en.wikipedia.org/wiki/Katakana
• Sokuon (Jul. 4, 2022, 15:46 UTC). In Wikipedia: The Free Encyclopedia. Retrieved from https://en.wikipedia.org/wiki/Sokuon

This commit DOESN’T support Kanji (Chinese characters) in Japanese because how to read it is highly dependent on context and the number of Kanji is much larger than those of Katakana and Hiragana.

[lart-rt]

Some commits are behind master branch, so I will resend a pull request after solving it.