feat(skills): add document-creator skill

cowork-complete-guide/skills/document-creator.md

@@ -0,0 +1,97 @@
+# Document Creator Skill
+
+## Identity
+When creating any document, spreadsheet, or presentation, follow these preferences exactly.
+
+---
+
+## Style: Black & White Modern
+
+### Color Palette
+- **Primary background**: White (`FFFFFF`)
+- **Primary text**: Near-black (`1A1A1A`)
+- **Accent / headers**: True black (`000000`)
+- **Secondary text / captions**: Medium gray (`666666`)
+- **Subtle backgrounds**: Light gray (`F5F5F5`)
+- **Borders / dividers**: Light gray (`E0E0E0`)
+- **Highlight / callout**: Black fill with white text
+- **No color accents** — no blues, greens, ambers, or brand colors unless explicitly requested
+
+### Typography
+- **Headers**: Georgia or Calibri Bold — clean, substantial
+- **Body**: Calibri or Arial — readable, modern
+- **Avoid**: decorative fonts, excessive italics, script fonts
+
+### Layout Principles
+- Generous white space — breathing room over density
+- Left-aligned text (never centered body copy)
+- Strong typographic hierarchy: large titles, medium subheads, small body
+- Minimal borders — use whitespace and background fills to separate sections, not heavy lines
+- No decorative elements — no gradients, no drop shadows on text, no clip art
+
+---
+
+## When to Use Each Format
+
+| Need | Format | Why |
+|------|--------|-----|
+| Data, numbers, calculations, comparisons | **Excel (.xlsx)** | Formulas stay live and editable |
+| Reports, memos, proposals, letters | **Word (.docx)** | Professional print/share format |
+| Investor decks, strategy presentations, board updates | **PowerPoint (.pptx)** | Visual storytelling, slide-by-slide flow |
+| Quick shareable summaries | **Markdown (.md)** | Fast, clean, works anywhere |
+
+**Default rule**: If the output will be shared externally or printed → use Word or PowerPoint. If it will be edited or updated regularly → use Excel.
+
+---
+
+## Default Document Structures
+
+### Excel Spreadsheets
+1. **Data sheet** — raw data with headers, no merged cells, freeze top row
+2. **Summary sheet** — SUMIF/COUNTIF aggregations, key totals
+3. **Charts sheet** — one chart per key insight
+- Always: black header row (white text), alternating light gray rows, totals row in black
+- Formulas over hardcoded values — everything should recalculate
+
+### PowerPoint Presentations
+Slide order:
+1. Title (black background, white text, subtitle)
+2. Executive Summary / The Situation
+3. Data / Evidence (charts or key stats)
+4. Recommendation or Strategy
+5. Implementation / Timeline
+6. Financials (if relevant)
+7. Risks & Mitigations
+8. Next Steps / Call to Action
+
+- Dark title slide + dark closing slide, light content slides ("sandwich")
+- Every slide needs one visual — chart, stat callout, table, or icon grid
+- No bullet-point-only slides
+- Speaker notes: include one sentence per slide summarizing the key point
+
+### Word Documents
+- Title + subtitle at top
+- Executive summary (3–5 sentences, no bullets)
+- Body in sections with bold headings
+- Conclusions section
+- Appendix for supporting detail
+- Page numbers, consistent margins (1 inch)
+
+---
+
+## Voice & Tone
+- **Direct and confident** — lead with the conclusion, support with evidence
+- **No jargon** — if a simpler word works, use it
+- **Data-backed** — quantify claims where possible ("~30% faster" not "significantly faster")
+- **No filler phrases** — avoid "it is important to note that", "in conclusion", "as mentioned above"
+- **Tien's preference**: modern, clean, no fluff
+
+---
+
+## What to Avoid
+- Colored backgrounds on content slides (except title/closing)
+- Bullet point walls — convert to cards, tables, or callout boxes
+- Redundant titles (slide title + section header saying the same thing)
+- Mixing font sizes randomly
+- Centering body text
+- Decorative accent lines under titles (AI-generated look — avoid)