Problem: runtime(tera): tera support can be improved
Solution: update tera filetype plugin, include a tera syntax script
include tera syntax tests, update the filetype test,
update makemenu and synmenu vim scripts
(MuntasirSZN)
closes: #16830
Signed-off-by: MuntasirSZN <muntasir.joypurhat@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>