Documentation Overhaul and version 0.8.0 update

[sinamsv]

This PR overhauls the project documentation to match the current 0.8.0 version of NumRS.

Major changes:

1. README.md: Now a high-level entry point with a concise quick start and deep links to detailed docs.
2. USAGE.md: Expanded to include detailed API documentation for matrix, tensor, math, ops, error, and parallel modules.
3. EXAMPLES.md: New file containing full, runnable code snippets for complex real-world use cases.
4. CHANGELOG.md: Added release notes for version 0.8.0, covering the new generic N-D Tensor implementation and randomness utilities.

All 49 unit tests passed successfully.

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PR created automatically by Jules for task 16729233037339898457 started by @sinamsv

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