Problem: filetype: karel files are not detected
Solution: detect '*.kl' files as karel filetype,
include syntax and filetype plugin
(Kirill Morozov)
closes: vim/vim#16075fdac54d7bb
Co-authored-by: Kirill Morozov <kirill@robotix.pro>
Co-authored-by: KnoP-01 <knosowski@graeffrobotics.de>