[Examples] Add real-time transcription script and accent post-processing notebook

[Aditi-M007]

This PR adds two practical, ready-to-run examples that significantly improve learning and adoption of Whisper, especially for non-English users.

New Files Added

• examples/real_time_transcription.py
  → Live microphone streaming transcription using pyaudio
  → Works out-of-the-box with tiny/base models for near real-time demo
  → Includes overlap buffer to avoid cutting words

• examples/accent_postprocessing.ipynb
  → Jupyter notebook demonstrating post-processing for Indian/accents
  → Uses spellchecker-py to correct common misrecognitions
  → Easy to extend with custom dictionaries

README Updated

Added section "New Usage Examples" with links to both files.

These examples directly address the suggestions:

"Create new Python scripts or Jupyter notebooks for niche tasks, like integrating with real-time audio streams or custom post-processing for accents."

Helps beginners and non-English speakers get started quickly.