Reorganize: Move all skills to skills/ folder

- Created skills/ directory
- Moved 272 skills to skills/ subfolder
- Kept agents/ at root level
- Kept installation scripts and docs at root level

Repository structure:
- skills/           - All 272 skills from skills.sh
- agents/           - Agent definitions
- *.sh, *.ps1       - Installation scripts
- README.md, etc.   - Documentation

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

skills/writing-clearly-and-concisely/skill.md

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+---
+name: writing-clearly-and-concisely
+description: Use when writing prose humans will read—documentation, commit messages, error messages, explanations, reports, or UI text. Applies Strunk's timeless rules for clearer, stronger, more professional writing.
+---
+
+# Writing Clearly and Concisely
+
+## Overview
+
+Write with clarity and force. This skill covers what to do (Strunk) and what not to do (AI patterns).
+
+## When to Use This Skill
+
+Use this skill whenever you write prose for humans:
+
+- Documentation, README files, technical explanations
+- Commit messages, pull request descriptions
+- Error messages, UI copy, help text, comments
+- Reports, summaries, or any explanation
+- Editing to improve clarity
+
+**If you're writing sentences for a human to read, use this skill.**
+
+## Limited Context Strategy
+
+When context is tight:
+
+1. Write your draft using judgment
+2. Dispatch a subagent with your draft and the relevant section file
+3. Have the subagent copyedit and return the revision
+
+Loading a single section (~1,000-4,500 tokens) instead of everything saves significant context.
+
+## Elements of Style
+
+William Strunk Jr.'s *The Elements of Style* (1918) teaches you to write clearly and cut ruthlessly.
+
+### Rules
+
+**Elementary Rules of Usage (Grammar/Punctuation)**:
+
+1. Form possessive singular by adding 's
+2. Use comma after each term in series except last
+3. Enclose parenthetic expressions between commas
+4. Comma before conjunction introducing co-ordinate clause
+5. Don't join independent clauses by comma
+6. Don't break sentences in two
+7. Participial phrase at beginning refers to grammatical subject
+
+**Elementary Principles of Composition**:
+
+8. One paragraph per topic
+9. Begin paragraph with topic sentence
+10. **Use active voice**
+11. **Put statements in positive form**
+12. **Use definite, specific, concrete language**
+13. **Omit needless words**
+14. Avoid succession of loose sentences
+15. Express co-ordinate ideas in similar form
+16. **Keep related words together**
+17. Keep to one tense in summaries
+18. **Place emphatic words at end of sentence**
+
+### Reference Files
+
+The rules above are summarized from Strunk's original text. For complete explanations with examples:
+
+| Section | File | ~Tokens |
+|---------|------|---------|
+| Grammar, punctuation, comma rules | `02-elementary-rules-of-usage.md` | 2,500 |
+| Paragraph structure, active voice, concision | `03-elementary-principles-of-composition.md` | 4,500 |
+| Headings, quotations, formatting | `04-a-few-matters-of-form.md` | 1,000 |
+| Word choice, common errors | `05-words-and-expressions-commonly-misused.md` | 4,000 |
+
+**Most tasks need only `03-elementary-principles-of-composition.md`** — it covers active voice, positive form, concrete language, and omitting needless words.
+
+## AI Writing Patterns to Avoid
+
+LLMs regress to statistical means, producing generic, puffy prose. Avoid:
+
+- **Puffery:** pivotal, crucial, vital, testament, enduring legacy
+- **Empty "-ing" phrases:** ensuring reliability, showcasing features, highlighting capabilities
+- **Promotional adjectives:** groundbreaking, seamless, robust, cutting-edge
+- **Overused AI vocabulary:** delve, leverage, multifaceted, foster, realm, tapestry
+- **Formatting overuse:** excessive bullets, emoji decorations, bold on every other word
+
+Be specific, not grandiose. Say what it actually does.
+
+For comprehensive research on why these patterns occur, see `signs-of-ai-writing.md`. Wikipedia editors developed this guide to detect AI-generated submissions — their patterns are well-documented and field-tested.
+
+## Bottom Line
+
+Writing for humans? Load the relevant section from `elements-of-style/` and apply the rules. For most tasks, `03-elementary-principles-of-composition.md` covers what matters most.