a half-baked "virtual" keyboard for Hebrew (think Lambdin)

Bemigot picked up this work and continues as esh-heb

JS skeleton modeled after Pāli keyboard as published by @siongui

TODO:

• add space key
• replace Holam after Vav with Holam Haser for Vav - defer until save/search
• on input force canonic order for accent mark, vowel sign and dagesh