Updates

[Factorization]

Various fixes to make all the processes start when the container is started.

The following changes were made:

1. Created shell script to start the container. This script runs the createindex.py if the index has needs to be built. Then starts the front end and backend services.
2. Added the missing pip package `langchain_community' to the requirements file.
3. Switch the python of the requirements to use pip-compile. Project dependencies need to be added to requirements.in file, then you run pip-compile --strip-extras --generate-hashes requirements.in to create the requirements.txt file.
4. Updated the createindex.py file to create a flag file when it is running and a flag file when it is complete.
5. Added example docker-compose.yml file.