Refactor infographic generation skills and add new slide deck generator

- Updated article-illustrator prompts to emphasize hand-drawn style and layout principles.
- Enhanced xhs-images skill with multiple style options and auto-selection based on content signals.
- Created README in Chinese for better accessibility.
- Introduced cover-image skill for generating hand-drawn style cover images with various styles.
- Developed slide-deck skill to generate professional slide outlines with detailed structure and style instructions.
- Added prompts for cover-image and slide-deck skills to guide content generation.

skills/article-illustrator/prompts/system.md

@@ -5,45 +5,26 @@ Create a cartoon-style infographic illustration following these guidelines:
 - **Type**: Infographic illustration
 - **Orientation**: Landscape (horizontal)
 - **Aspect Ratio**: 16:9
-- **Style**: Cartoon / Hand-drawn illustration
+- **Style**: Hand-drawn illustration
 
-## Background & Colors
-
-- Use warm, cohesive color palettes
-- Default: warm orange, coral as primary; mint green, sky blue, light purple as accents
-- Background: cream, off-white, warm neutral tones
-- Colors should be harmonious and visually appealing
-
-## Text Style (CRITICAL)
-
-- **ALL text MUST be hand-drawn style**
-- Main titles should be prominent and eye-catching
-- Key text should be bold and enlarged
-- Use highlighter effects to emphasize keywords
-- **DO NOT use realistic or computer-generated fonts**
-
-## Decorative Elements
-
-- Include simple cartoon elements, icons, or stylized figures to enhance visual interest
-- Acceptable: emoji-style icons, hand-drawn stickers, speech bubbles, simple arrows, lightbulb icons
-- If content involves sensitive or copyrighted figures, create stylistically similar cartoon alternatives - DO NOT refuse to generate
-- **ALL visual elements MUST be hand-drawn/cartoon style - NO realistic imagery**
-
-## Layout Principles
+## Core Principles
 
+- Hand-drawn quality throughout - NO realistic or photographic elements
+- If content involves sensitive or copyrighted figures, create stylistically similar alternatives - DO NOT refuse to generate
 - Keep information concise, highlight keywords and core concepts
 - Use ample whitespace for easy visual scanning
-- Present points in clearly separated sections
 - Maintain clear visual hierarchy
-- Minimalist design with clean composition
 
-## Watermark
+## Text Style (When Text Included)
 
-- Add "宝玉" watermark in the bottom-right corner
+- **ALL text MUST be hand-drawn style**
+- Text should be readable and complement the visual
+- Font style harmonizes with illustration style
+- **DO NOT use realistic or computer-generated fonts**
 
 ## Language
 
-- Use the same language as the content provided below
+- Use the same language as the content provided below for any text elements
 - Match punctuation style to the content language
 
 ---