[DMP 2026]: Intelligent closed caption generation pipeline

[Aditi2k5]

This pull request outlines the following:

1. Updated working CC Generation tool code in panns_pipeline.py file

• Uses PANNs + Florence Vision Model + SileroVAD + Sentence Transformers + GPT-4o together to create, generate and refine meaningful captions
• Langsmith and Langchain integrated for API keys cost logging and token usage tracking

2. Updated README file outlining current progress, milestones reached, results and tech stack.
3. Results present in 2 folders mainly:

• results_v5: of shorter test results
• results_v14: of the latest test results used on 22 minute video