Add script to augment movie descriptions in markdown table

- Implemented a new Python script `augment_movies_with_descriptions.py` to enhance movie entries in a markdown file with descriptions fetched from the OMDb API.
- The script processes a markdown table, adding a "Beschreibung" column if missing and populating it with either generated or fetched descriptions based on the movie's title, year, and genre.
- Introduced caching mechanism to minimize API requests and avoid exceeding rate limits.
- Added command-line arguments for API key, request limits, and a force option to override existing descriptions.

Author: 0xfab1