Wanted to get the code up here in case there was some discussion on how to do things. Will look into the documentation tomorrow.

Got a little stuck on theold_version_test needed to have the pyscopg extras installed, not sure how litellm is working. I updated the make target to include all extras when testing python 3.9. Let me know if this isn't the path you'd prefer.

I took a stab at documentation. Open to feedback on structuring. Overall I wanted the postgres session to be in extensions because psycopg can be somewhat heavy on certain platforms. But I wasn't sure if the docs should go with extensions or the other memory docs.