Restructure challenges into organized monthly system

- Create challenges/ directory structure with monthly subfolders
- Move October challenge to challenges/October-2025/readme.md
- Create challenge template in challenges/readme.md
- Add November 2025 placeholder in challenges/November-2025/readme.md
- Convert challenges.md to summary page with links and archive
- Update image paths for October challenge screenshots
- Add comprehensive challenge participation and development info

challenges/November-2025/readme.md

@@ -0,0 +1,72 @@
+---
+gitea: none
+include_toc: true
+---
+
+# November 2025 Challenge: "[Challenge Name TBD]"
+
+## Challenge Overview
+
+[Challenge description and theme to be determined]
+
+## Challenge Rules
+
+### Materials & Constraints
+
+- **Filament**: [To be specified]
+- **Maximum Filament Usage**: [To be determined]
+- **Model Specification**: [To be determined]
+- **Print Mode**: [To be specified]
+
+### Competition Categories
+
+- **[Category 1]**: [To be determined]
+- **[Category 2]**: [To be determined]
+- **Overall Winner**: Best overall submission
+
+### Judging Criteria
+
+1. **[Criteria 1]** ([%]): [To be determined]
+2. **[Criteria 2]** ([%]): [To be determined]
+3. **[Criteria 3]** ([%]): [To be determined]
+4. **Challenge Adherence** (10%): Following all challenge requirements
+
+### Submission Requirements
+
+- **[Requirement 1]**: [To be determined]
+- **Documentation**: Include photos showing [specific aspects]
+- **Settings Documentation**: Share printer settings used
+- **Process Notes**: Brief description of techniques used
+
+### Evaluation Process
+
+- **[Evaluation Method]**: [To be determined]
+- **Community Voting**: People's choice award
+- **Technical Review**: Expert panel assessment
+
+## Prizes & Recognition
+
+### Awards
+
+- **[Award 1]**: Recognition + prize
+- **[Award 2]**: Recognition + prize
+- **Overall Winner**: Grand prize + recognition
+- **People's Choice Award**: Community favorite
+- **Innovation Award**: Most creative technique
+
+### Documentation
+
+- Winner photos for social media sharing
+- Video documentation of winning techniques
+- Settings and process sharing for community learning
+
+## Timeline
+
+- **Challenge Announcement**: [Date TBD]
+- **Submission Deadline**: [Date TBD]
+- **Judging Period**: [Date Range TBD]
+- **Winner Announcement**: [Date TBD]
+
+## Model Creation Instructions
+
+[To be determined based on challenge requirements]