Code clean up and documentation update

[shashankmc]

• [x] Archive and delete branches
• [x] Remove unused or old code
• [x] Merge airflow to master branch
• [ ] Update documentation with the new steps to run the ETL pipeline
• [ ] Check CI/CD pipeline for docker image publishing (update respective branch - airflow to master in workflow, change tag to latest rather than airflow)
• [x] Change published packages to public (with respect to docker image)

[shashankmc]

I've made the docker image publicly accessible @Cloud956

[shashankmc]

@davidwickerhf Could you please look into the pending task of CI/CD pipeline?