Release v1.2.0: Major feature additions

- Add PowerPoint export (PPTX/ODP) with slide-level formatting
- Add comprehensive document conversion menu with import/export
- Add interactive table creation helper in markdown editor
- Update documentation with all new features and version history
- Improve menu organization for better user experience

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

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

package.json

@@ -1,6 +1,6 @@
 {
   "name": "pan-converter",
-  "version": "1.1.0",
+  "version": "1.2.0",
   "description": "Cross-platform Markdown editor and converter using Pandoc",
   "main": "src/main.js",
   "scripts": {