Updates

I've updated the calligraphy for Vajrasattva and the Heart Sūtra. Also updated the notes on the Heart Sūtra and linked to my synopsis of Jan Nattier's article on where the sūtra was composed (China rather than India almost certainly). I added the Uchen script the Śuddha mantra (aka the Śunyata Mantra) - using an image of the font Tibetan Machine Uni which I have resorted to instead of calligraphy.