feat(command): add easter egg command /omomomo

Adds a fun easter egg command that explains what Oh My OpenCode is about.
Shows project overview, features, and credits when invoked.

🤖 GENERATED WITH ASSISTANCE OF [OhMyOpenCode](https://github.com/code-yeongyu/oh-my-opencode)

.opencode/command/omomomo.md

@@ -0,0 +1,37 @@
+---
+description: Easter egg command - about oh-my-opencode
+---
+
+<command-instruction>
+You found an easter egg! 🥚✨
+
+Print the following message to the user EXACTLY as written (in a friendly, celebratory tone):
+
+---
+
+# 🎉 oMoMoMoMoMo···
+
+**You found the easter egg!** 🥚✨
+
+## What is Oh My OpenCode?
+
+**Oh My OpenCode** is a powerful OpenCode plugin that transforms your AI agent into a full development team:
+
+- 🤖 **Multi-Agent Orchestration**: Oracle (GPT-5.2), Librarian (Claude), Explore (Grok), Frontend Engineer (Gemini), and more
+- 🔧 **LSP Tools**: Full IDE capabilities for your agents - hover, goto definition, find references, rename, code actions
+- 🔍 **AST-Grep**: Structural code search and replace across 25 languages
+- 📚 **Built-in MCPs**: Context7 for docs, Exa for web search, grep.app for GitHub code search
+- 🔄 **Background Agents**: Run multiple agents in parallel like a real dev team
+- 🎯 **Claude Code Compatibility**: Your existing Claude Code config just works
+
+## Who Made This?
+
+Created with ❤️ by **[code-yeongyu](https://github.com/code-yeongyu)**
+
+🔗 **GitHub**: https://github.com/code-yeongyu/oh-my-opencode
+
+---
+
+*Enjoy coding on steroids!* 🚀
+
+</command-instruction>