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/readme.md

@@ -0,0 +1,91 @@
+# Challenge Template
+
+## [Month Year] Challenge: "[Challenge Name]"
+
+### Challenge Overview
+
+[Brief description of the challenge theme and goals]
+
+### Challenge Rules
+
+#### Materials & Constraints
+
+- **Filament**: [Specify required filament type/brand]
+- **Maximum Filament Usage**: [Weight limit if applicable]
+- **Model Specification**: [Dimensions, complexity, or provided model details]
+- **Print Mode**: [Any specific printing requirements]
+
+#### Competition Categories
+
+- **[Category 1]**: [Description]
+- **[Category 2]**: [Description]
+- **[Overall Winner]**: [Description]
+
+#### Judging Criteria
+
+1. **[Criteria 1]** ([%]): [Description]
+2. **[Criteria 2]** ([%]): [Description]
+3. **[Criteria 3]** ([%]): [Description]
+4. **[Criteria 4]** ([%]): [Description]
+
+#### Submission Requirements
+
+- **[Requirement 1]**: [Description]
+- **[Requirement 2]**: [Description]
+- **Documentation**: Include photos showing [specific aspects]
+- **Settings Documentation**: Share printer settings used
+- **Process Notes**: Brief description of techniques used
+
+#### Evaluation Process
+
+- **[Evaluation Method 1]**: [Description]
+- **[Evaluation Method 2]**: [Description]
+- **Community Voting**: [Description]
+- **Technical Review**: [Description]
+
+### Prizes & Recognition
+
+#### Awards
+
+- **[Award 1]**: [Description]
+- **[Award 2]**: [Description]
+- **[Award 3]**: [Description]
+- **People's Choice Award**: Community favorite
+- **Innovation Award**: [Description]
+
+#### Documentation
+
+- Winner photos for social media sharing
+- Video documentation of winning techniques
+- Settings and process sharing for community learning
+
+### Timeline
+
+- **Challenge Announcement**: [Date]
+- **[Key Milestone]**: [Date]
+- **Submission Deadline**: [Date]
+- **Judging Period**: [Date Range]
+- **Winner Announcement**: [Date]
+
+### [Model Creation/Setup Instructions]
+
+#### [Software/Method 1]
+
+**Step 1: [Action]**
+
+1. [Instruction]
+2. [Instruction]
+3. [Instruction]
+
+**Step 2: [Action]**
+
+1. [Instruction]
+2. [Instruction]
+3. [Instruction]
+
+#### Alternative Methods
+
+- **[Software 1]**: [Brief instructions]
+- **[Software 2]**: [Brief instructions]
+- **[Software 3]**: [Brief instructions]
+- **Any CAD Software**: [General guidance]