recommendation pipeline diagram

[riddhima-7321]

Add Recommendation System ML Pipeline Diagram

This PR adds a comprehensive real-time recommendation system pipeline diagram showcasing the complete ML workflow from data ingestion to model serving.

Pipeline Components:

• Real-time data ingestion with Kafka streaming
• Batch and stream processing with Apache Spark
• Airflow orchestration for workflow scheduling
• Feature engineering and storage layer
• ML training pipeline with model registry
• Real-time serving with caching (Redis)
• Pre-computed recommendations storage
• Feedback loop for continuous improvement

File Added:
-recommendation_system_pipeline.py - Generates the ML pipeline architecture diagram

Reference:
Based on real-time recommender system architectures: https://medium.com/@fengyuxian1994/part-2-realtime-recommender-system-ml-pipeline-with-airflow-a0f5e859558f

Resolves: #9