I have been going through the Grav Documentation which has been helpful and also through the forums. I seen mention of a possible Grav Development Training Course and wondered if there was ever anything like this developed.
I would also be interested in any links to good documentation for learning to work with Twig, Below are some I have found.
Twig Resources:
http://twig.sensiolabs.org/
https://knpuniversity.com/screencast/twig
Thank you.