Add COBOL syntax

I took what was proposed on bugs.kde.org: https://bugs.kde.org/show_bug.cgi?id=462944#c3 and made several changes.

However, I don't know what to do about the license, when can it be considered as a new creation?

For the moment I added `author="Jonathan Poelen (jonathan.poelen@gmail.com);github.com/MihailJP" license="MIT"`. So there are 2 authors, is it a problem?

FEATURE: 462944