Revise README for wax11 shader project

[NickCody]

Updated README to reflect project rebranding and added detailed installation and usage instructions for the wax11 shader.

Description

Motivation and Context

Type of Change

• Bug fix (non-breaking change that fixes an issue)
• New feature (non-breaking change that adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update
• Performance improvement
• Code refactoring
• Build/CI configuration

Testing Performed

• Ran just validate locally (build + tests + clippy)
• Tested with just run-demo
• Tested with just run-playlist
• Added new tests for the changes
• All existing tests pass

Manual Testing

# Example commands you used for testing
wax11 --window --shadertoy https://www.shadertoy.com/view/3dXyWj

Screenshots/Demos

Checklist

• My code follows the project's code style (cargo fmt --all)
• I have run cargo clippy and resolved all warnings
• I have added tests that prove my fix is effective or that my feature works
• All new and existing tests pass (cargo test --verbose)
• I have updated the documentation (if applicable)
• I have added an entry to CHANGELOG.md (for notable changes)
• My commits follow the project's commit message conventions
• I have rebased my branch on the latest main

Additional Notes