Update README.md

Fix folder structure formatting in README

Add README for OpenSourceLens pipeline

Ignore macOS .DS_Store files

Reorganized project structure and added Airflow DAGs and pipeline data

Added aggregations to gold layer for repo health score, branch activity distribution, and contributor consistency

Completed Silver table creation and transformation using Apache Iceberg

Add Bronze to Silver transformation, flatten PushEvent data

Initial load of GitHub archive data from S3 and load to Spark (cleaned bytecode)

ingestion : add logging, error handling, and debug helper script

Ingestion script: walk‑back logic + download working

Add build_s3_key helper and sample test output

Initial project scaffold and last_completed_hour_utc helper