remove requirements.txt and small update of readme

Author: paulparkinson

python-rag-chatbot/README.md

@@ -11,7 +11,7 @@
 
 - setup ~/.oci/config
 - set yourcompartmentid
-- podman run -d --name 23ai -p 1521:1521 -e ORACLE_PWD=Welcome12345 -v oracle-volume:/Users/pparkins/oradata container-registry.oracle.com/database/free:latest
+- podman run -d --name 23ai -p 1521:1521 -e ORACLE_PWD=<password> -v oracle-volume:/Users/pparkins/oradata container-registry.oracle.com/database/free:latest
 - create/config vector tablespace and user
 - add oracle database info for use in init_rag_streamlit.py / init_rag_streamlit_exp.py
 - run run_oracle_bot.sh /run_oracle_bot_exp.sh