feat: Add OurDigital custom skills package (10 skills)

Complete implementation of OurDigital skills with dual-platform support
(Claude Desktop + Claude Code) following standardized structure.

Skills created:
- 01-ourdigital-brand-guide: Brand reference & style guidelines
- 02-ourdigital-blog: Korean blog drafts (blog.ourdigital.org)
- 03-ourdigital-journal: English essays (journal.ourdigital.org)
- 04-ourdigital-research: Research prompts & workflows
- 05-ourdigital-document: Notion-to-presentation pipeline
- 06-ourdigital-designer: Visual/image prompt generation
- 07-ourdigital-ad-manager: Ad copywriting & keyword research
- 08-ourdigital-trainer: Training materials & workshop planning
- 09-ourdigital-backoffice: Quotes, proposals, cost analysis
- 10-ourdigital-skill-creator: Meta skill for creating new skills

Features:
- YAML frontmatter with "ourdigital" or "our" prefix triggers
- Standardized directory structure (code/, desktop/, shared/, docs/)
- Shared environment setup (_ourdigital-shared/)
- Comprehensive reference documentation
- Cross-skill integration support

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

custom-skills/05-ourdigital-document/code/assets/brand_config.json

@@ -0,0 +1,108 @@
+{
+  "name": "Corporate Brand Guidelines",
+  "version": "1.0",
+  "colors": {
+    "primary": "#1a73e8",
+    "secondary": "#34a853",
+    "accent": "#ea4335",
+    "warning": "#fbbc04",
+    "dark": "#202124",
+    "light": "#f8f9fa",
+    "text": "#3c4043",
+    "subtext": "#5f6368",
+    "background": "#ffffff",
+    "surface": "#f1f3f4"
+  },
+  "fonts": {
+    "heading": "Poppins",
+    "subheading": "Poppins",
+    "body": "Lora",
+    "caption": "Arial",
+    "fallback": {
+      "heading": "Arial",
+      "body": "Georgia"
+    }
+  },
+  "typography": {
+    "title": {
+      "size": 44,
+      "weight": "bold",
+      "lineHeight": 1.2
+    },
+    "heading1": {
+      "size": 32,
+      "weight": "bold",
+      "lineHeight": 1.3
+    },
+    "heading2": {
+      "size": 24,
+      "weight": "semibold",
+      "lineHeight": 1.4
+    },
+    "body": {
+      "size": 18,
+      "weight": "normal",
+      "lineHeight": 1.6
+    },
+    "caption": {
+      "size": 14,
+      "weight": "normal",
+      "lineHeight": 1.5
+    }
+  },
+  "logos": {
+    "primary": "assets/media/logo.png",
+    "secondary": "assets/media/logo_white.png",
+    "icon": "assets/media/icon.png"
+  },
+  "spacing": {
+    "small": 8,
+    "medium": 16,
+    "large": 24,
+    "xlarge": 32
+  },
+  "borderRadius": {
+    "small": 4,
+    "medium": 8,
+    "large": 12
+  },
+  "shadows": {
+    "small": "0 1px 3px rgba(0,0,0,0.12)",
+    "medium": "0 4px 6px rgba(0,0,0,0.16)",
+    "large": "0 10px 20px rgba(0,0,0,0.19)"
+  },
+  "animations": {
+    "transition": "all 0.3s ease",
+    "fadeIn": "fadeIn 0.5s ease-in",
+    "slideIn": "slideIn 0.3s ease-out"
+  },
+  "layouts": {
+    "slideMargins": {
+      "top": 0.5,
+      "right": 0.5,
+      "bottom": 0.5,
+      "left": 0.5
+    },
+    "contentPadding": {
+      "top": 1.5,
+      "right": 1,
+      "bottom": 1,
+      "left": 1
+    }
+  },
+  "chartColors": [
+    "#1a73e8",
+    "#34a853",
+    "#fbbc04",
+    "#ea4335",
+    "#9333ea",
+    "#06b6d4",
+    "#f97316",
+    "#84cc16"
+  ],
+  "gradients": {
+    "primary": "linear-gradient(135deg, #1a73e8 0%, #34a853 100%)",
+    "secondary": "linear-gradient(135deg, #34a853 0%, #fbbc04 100%)",
+    "accent": "linear-gradient(135deg, #ea4335 0%, #fbbc04 100%)"
+  }
+}