refactor: reorganize documentation structure

- Remove docs/ from .gitignore to track documentation files
- Delete completed plan documents (encrypted-config-plan.md, updater-plan.md)
- Add roadmap.md with project milestones and future features

docs/roadmap.md

@@ -0,0 +1,7 @@
+- 自动升级自定义路径 ✅
+- win 绿色版报毒问题 ✅
+- mcp 管理器
+- i18n
+- gemini cli
+- homebrew 支持
+- 自定义 vscode 路径