Delta Compositor: Documentation

All documentation is currently in the Docs folder within the main source tarball. It consists of four parts:

1. The User guide for end users, which describes the way Delta is used and how to use DeltaScript
2. The Design guide for maintainers and developers, which describes how Delta is written
3. The node documentation which describes each node (in Docs/nodes)The type documentation which describes each of Delta's data types (in Docs/types)