docs: modularize documentation and update project branding

This commit performs a major overhaul of the documentation architecture. The
previous flat markdown files have been replaced by a structured series of
numbered guides to improve discoverability and readability.

Key changes:
- Migrated content into 9 modular guides within the guides directory
- Rewrote README.md for better clarity and faster onboarding
- Added project branding assets, including a new SVG logo
- Updated mix.exs to support grouped extras in HexDocs for better navigation
- Refactored the examples catalog and updated the example index
- Introduced a bash script to automate the execution of all examples
- Removed redundant legacy documentation files

This structure ensures that the documentation scales with the project and
provides a clear learning path for both basic and advanced features.

Author: nshkrdotcom