Updated code with greeting support

Log google drive documents in the mongodb, add source of the document and made chunks to overlap text.

Updated embedding to produciton, changed the depenedency for magic library

Updarte chatbot with deployment configurations on the Render

DOne some testing and fixed the retrieving context by date.

Changes to be committed:

Implementation for Google drive is done. Now it is working fine, except need a new function that can delete the chunks if a document is removed from google drive.