I've found a solution by myself.
In the Joomla folder go to
administrator/components/com_scriptcodehighlighter/models/forms and open the file
scriptcodehighlighter.xml. There's the list of all supported formats.
Then add following options:
Just for be sure, I've followed the alphabetical order of the file, so I've put them in right positions (but I don't know if it's has any importance).
Do the same thing for the file
Now when I add the code in the dropdown list I can see missing languages, and they also work correctly in article.