docs: Update skill counts to accurate numbers (350+ skills)

Updated all skill count references from outdated 283/292 to current 350+:
- Badge: 292 → 350+
- Main text: 283 → 350+
- Installation: 292 → 350+
- Footer: 283 → 350+
- Gateway Agent Skills: 31 → 41 (accurate count)
- Categories: 33 → 35+ (approximate)

Actual count: 354 skills across 35+ categories
- 348 in category directories
- 6 at root level
- 41 gateway Agent Skills (discover-* directories)

Author: rand

README.md

@@ -1,7 +1,7 @@
 # Atomic Skills for Claude Code
 
 [![Claude Code Plugin](https://img.shields.io/badge/Claude%20Code-Plugin-blue)](https://docs.claude.com/en/docs/claude-code/plugins)
-[![Skills](https://img.shields.io/badge/Skills-292-green)](skills/)
+[![Skills](https://img.shields.io/badge/Skills-350+-green)](skills/)
 [![License](https://img.shields.io/badge/License-MIT-yellow)](LICENSE)
 
 **Context-efficient development knowledge via progressive skill discovery**
@@ -21,7 +21,7 @@ This creates an challenging tradeoff between comprehensive coverage and context
 
 ## The Solution: Atomic Skills + Progressive Discovery
 
-### Atomic Skills (283 total)
+### Atomic Skills (350+ total)
 Each skill is **focused, self-contained, and composable**:
 - Average 320 lines - small enough to load quickly
 - Single responsibility - covers one clear topic
@@ -157,7 +157,7 @@ Complete implementation guides loaded only when needed:
 /plugin install https://github.com/rand/cc-polymath
 ```
 
-That's it! All 292 skills and the `/skills` command are immediately available.
+That's it! All 350+ skills and the `/skills` command are immediately available.
 
 **For local development or testing**:
 ```bash
@@ -516,4 +516,4 @@ Feel free to fork and adapt for your own use. Pull requests welcome.
 
 ---
 
-**283 atomic skills** • **31 gateway Agent Skills** • **33 categories** • **100% CI-validated**
+**350+ atomic skills** • **41 gateway Agent Skills** • **35+ categories** • **100% CI-validated**