Figured it out.
Looking at the
source for OScriptManager (the line highlighted), it binds an instance of "OScriptDocumentDatabaseWrapper" to the variable "db" and an instance of "OScriptOrientWrapper" to the variable "orient" - This means we can access all the methods inside the above Java classes from JavaScript via the above variables.
Therefore, the Java Docs for the above two classes essentially becomes the docs for the JavaScript API.
Not too sure whether this is the absolute truth, but it works for me :)