I've been researching this myself and found the following Psionics Handbook. It's been vetted by the Reddit community and contains all 20 levels of the Mystic class originally presented by Wizards of the Coast. Along with help from the community, the author took the class to next level status and after playing a Psionic character, I highly recommend it. I'm hoping we can get someone from the community to add it to the Community pack. I have been trying myself, but I'm completely new to adding class content and it's been a very slow process. Check it out here:
https://drive.google.com/file/d/0B2b...BVRDVOXzA/view
Here's the Reddit thread:
https://www.reddit.com/r/UnearthedAr...ntinuation_of/