Feat/documentation (8/8)

[bnomei]

Linked Issue

Closes #

Description

Refresh documentation to reflect TOON v3.0 compliance and current behavior. This updates README badges and spec links, documents numeric precision and special values, expands crate and public API docs, and adds standard examples and CLI usage notes. This is PR 8 of 8 in the intended sequence (1-8).

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
• Refactoring (no functional changes)
• Performance improvement
• Test coverage improvement

Changes Made

• Update README badges/spec links and document numeric precision and special values.
• Refresh crate-level docs and public API doc comments with current behavior.
• Add standard examples and CLI usage documentation.

SPEC Compliance

• This PR implements/fixes spec compliance
• Spec section(s) affected:
• Spec version:

Testing

• All existing tests pass
• Added new tests for changes
• Tests cover edge cases and spec compliance

Docs-only change; no tests run.

Pre-submission Checklist

• My code follows the project's coding standards
• I have run code formatting/linting tools
• I have added tests that prove my fix/feature works
• New and existing tests pass locally
• I have updated documentation if needed
• I have reviewed the TOON specification for relevant sections

Breaking Changes

• No breaking changes
• Breaking changes (describe migration path below)

Migration path:

Additional Context

Branch: feat/documentation
Intended PR order: 1-8 (this is PR 8 of 8)