Add gemini-imagegen skill and fix component counts

- Add gemini-imagegen skill for image generation with Gemini API
- Fix component counts: 17 agents (was 15), 6 commands, 1 skill
- Add comprehensive README documenting all components
- Add CHANGELOG tracking version history
- Bump version to 1.1.0

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

plugins/compounding-engineering/.claude-plugin/plugin.json

@@ -1,7 +1,7 @@
 {
   "name": "compounding-engineering",
-  "version": "1.0.0",
-  "description": "AI-powered development tools that get smarter with every use. Make each unit of engineering work easier than the last. Includes 15 specialized agents and 6 commands.",
+  "version": "1.1.0",
+  "description": "AI-powered development tools that get smarter with every use. Make each unit of engineering work easier than the last. Includes 17 specialized agents, 6 commands, and 1 skill.",
   "author": {
     "name": "Kieran Klaassen",
     "email": "kieran@every.to",
@@ -16,6 +16,7 @@
     "workflow-automation",
     "code-review",
     "quality",
-    "knowledge-management"
+    "knowledge-management",
+    "image-generation"
   ]
 }