Add before/after examples for Data Engineer roles

[SaharPak]

Description

Add role-specific before/after CV examples for Data Engineers to the EXAMPLES.md file.

What to include

• 3-5 before/after bullet point transformations for Data Engineer CVs
• Focus on common weak patterns (vague pipeline descriptions, missing scale metrics)
• Show how to highlight: data pipeline scale (TB/day), latency improvements, cost savings
• Tools to emphasize: Spark, Airflow, dbt, Snowflake, BigQuery, Kafka, etc.
• Example of transforming a generic "built data pipelines" into a specific, quantified achievement

How to contribute

1. Fork the repo
2. Add a "Data Engineer" section to EXAMPLES.md
3. Follow the existing before/after format
4. Open a PR with your changes