docs: update benchmark charts and index for improved clarity and usability (#125)

- Refactored `charts.html` to enhance the loading mechanism and improve the user experience for both JavaScript-enabled and disabled environments.
- Updated the Content Security Policy (CSP) for better security compliance and maintainability.
- Revised the benchmark index to improve the organization of policy performance metrics, ensuring a clearer comparison across different cache policies.
- Enhanced documentation to reflect changes in the charts structure and benchmark results, facilitating better understanding for users.

These updates improve the overall clarity and usability of benchmark results, making it easier for users to interpret performance metrics.

Author: TKorr