Refine repository structure for KiCad 9 optimization

- Add dedicated /kicad/ directory with organized subdirectories for libraries, schematics, gerbers, plots, and backups
- Create comprehensive KiCad 9 library structure (symbols, footprints, 3D models)
- Add manufacturing-ready directories for production files (gerbers, drill, pick-and-place)
- Update all README files with KiCad-specific documentation and workflows
- Add KiCad-optimized .gitignore file for proper version control
- Create KICAD-PROJECT-TEMPLATE.md comprehensive usage guide
- Add hardware assembly documentation and BOM management
- Include detailed manufacturing file generation instructions
- Add docs structure with design-notes and user-manual directories
- Provide complete workflow from design to manufacturing with quality checklists

kicad/libraries/footprints/README.md

@@ -0,0 +1,54 @@
+# /kicad/libraries/footprints
+
+Custom footprints for your KiCad project.
+
+## File Format
+- Footprints are stored in `.pretty` directories
+- Each `.pretty` directory is a footprint library
+- Individual footprints are `.kicad_mod` files within the `.pretty` directory
+
+## Naming Convention
+- Library directories: `ProjectName_ComponentType.pretty`
+- Footprint files: `ComponentName.kicad_mod`
+- Examples:
+  - `MyProject_Connectors.pretty/`
+    - `USB-C_Receptacle.kicad_mod`
+    - `Header_2x10_2.54mm.kicad_mod`
+  - `MyProject_MCU.pretty/`
+    - `STM32F4_LQFP64.kicad_mod`
+
+## Footprint Creation Guidelines
+- Include proper pad sizes and drill holes
+- Add courtyard layer (F.CrtYd/B.CrtYd) with 0.25mm clearance minimum
+- Include fabrication layer (F.Fab/B.Fab) with component outline
+- Add silkscreen layer (F.SilkS/B.SilkS) for component identification
+- Set reference designator and value positions
+- Include 3D model associations when available
+
+## Layer Guidelines
+- **F.Cu/B.Cu**: Copper pads and traces
+- **F.SilkS/B.SilkS**: Silkscreen printing
+- **F.Fab/B.Fab**: Fabrication layer (component outline)
+- **F.CrtYd/B.CrtYd**: Courtyard (component keepout area)
+- **F.Mask/B.Mask**: Solder mask openings
+
+## Adding to Project
+1. Open KiCad Project Manager
+2. Go to **Preferences → Manage Footprint Libraries**
+3. Click **Add** and browse to this directory
+4. Select your `.pretty` directory
+5. Set library nickname and path (use relative paths)
+
+## Example Library Structure
+```
+footprints/
+├── MyProject_Connectors.pretty/
+│   ├── USB-C_Receptacle.kicad_mod
+│   ├── Header_2x10_2.54mm.kicad_mod
+│   └── Terminal_Block_3pin.kicad_mod
+├── MyProject_MCU.pretty/
+│   ├── STM32F4_LQFP64.kicad_mod
+│   └── ESP32_Module.kicad_mod
+└── MyProject_Sensors.pretty/
+    ├── BME280_LGA8.kicad_mod
+    └── MPU6050_QFN24.kicad_mod