Added Receipt Example

[meghana1090]

I've added a new receipt processing example: a receipt_processor.py that processes receipt images using Tesseract OCR and a test case in test_receipt_processor.py to ensure functionality and validate the structure

The receipt processor extracts:

• Merchant name
• Date
• Total amount
• Tax amount
• Payment method
• Individual items with:
  • Description
  • Quantity
  • Unit price
  • Total price

It is similar to the resume processor example, but tailored for receipt processing use cases.