Appium developer documents

Our team are trying to develop cocos2d-x webdriver for appium 1.5.

Currently, I’m developing this webdriver based on appium-fake-driver, and I’m also reading other drivers, appium source code for understanding appium architecture.

If I can read developer documents, it seems that increasing the development speed.(e.g how to debug driver, appium 1.5 architecture and how to contribute…)
Would you tell me if where is those documents?