* integrate langchain
get rid of mongodb
use llama-cpp-python bindings
* fixed most chat endpoints except posting questions
* Working post endpoint !
* everything works except streaming
* current state
* streaming as is
* got rid of langchain wrapper for calling llm, went back to using bindings directly
* working streaming
* sort chats by time
* cleaned up styling and added back loading indicator
* Add persistence support to redis
* fixed tooltips
* fixed default prompts
* added link to api docs (closes How to use the api #155 )
