Added developer documentation.
Added developer documentation.

bendmorris/retriever,goelakash/retriever,davharris/retriever,bendmorris/retriever,davharris/retriever,embaldridge/retriever,davharris/retriever,embaldridge/retriever,henrykironde/deletedret,bendmorris/retriever,embaldridge/retriever,henrykironde/deletedret,goelakash/retriever