docs: Update README.md for v2.0.0 release preparation

- Rewrites Installation section for clarity (Community Plugin vs Manual Release).
- Adds dedicated Configuration and Using the Python Library sections.
- Updates Key Features list with latest functionalities.
- Adds important note regarding recommended script structure for discovery.
- Updates Support the Project section with more context.
- Moves developer setup instructions to Contributing section.
- General structure and Table of Contents updates.

Author: mathe00