Plain text language listed as 'plaintext'

I just noticed that plain text "language" is listed as plaintext in the language dropdown:

The generated language-names.php includes this:

https://github.com/westonruter/syntax-highlighting-code-block/blob/48374609f157de43e30a7500a1010aed7d13a9be/language-names.php#L130

Apparently this needs to be a special case added to generate-language-names.php.