Create USERS_START_HERE.md documentation

[Thinkersbluff]

Create primary user documentation for 3D printer owners.

Tasks:

• "I Just Want Firmware" section with download links
• Hardware Compatibility Guide with simple decision tree
• Flashing Instructions with pictures and simple language
• Basic Configuration for common modifications
• Troubleshooting in plain English
• When to Ask for Help and community support info

Acceptance Criteria:

• Non-technical users can successfully use firmware
• Simple, jargon-free language throughout
• Clear decision trees for hardware compatibility
• Troubleshooting covers common issues

Dependencies: Move documentation files
Estimate: 5 story points

[Thinkersbluff]

Accidentally created - cleaning up