📜 Modernize README to entreprise standards + compliance documentation

[RichardNk24]

## Summary
This PR aligns our documentation with enterprise requirements for:
- HIPAA/GDPR compliance visibility
- Developer onboarding efficiency 
- Third-party integration clarity

## Changes
### Added
- Compliance section with regulatory badges
- Quick Start guide for accelerated onboarding
- Table of Contents with deep linking
- Security best practices documentation
- Testing/validation guidance

### Changed
- Restructured content hierarchy for clinical developer workflows
- Converted environment table to markdown format
- Added Vital-branded status badges

### Removed
- Redundant installation instructions
- Consolidated duplicate error handling examples

## Compliance Impact
- [x] Requires Legal Review (PHI documentation)
- [x] Affects Partner SDK Guidelines
- [ ] Changes API Surface

## Testing Validation

```bash
# Verified documentation renders correctly in:
- [x] GitHub UI
- [x] PyPI project page
- [x] VS Code Markdown Preview

Related

• Internal Documentation Standard DOC-101
• HIPAA Documentation Policy §4.2

Deployment Notes

- No code changes - pure documentation update
+ Requires versioned release for audit trail
! Must merge with squash to preserve commit history

This structure:  
1. Meets healthcare compliance requirements  (from my own research)
2. Provides technical clarity for engineers  
3. Includes legal/compliance tracking  
4. Maintains enterprise audit standards  
5. Aligns with Fortune 500 PR conventions


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_Suggested Reviewers_

`@vital-team/docs-owners`  
`@vital-compliance/legal`  
`@vital-devrel/partner-team`

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