feat: add storage notice to top page

fix: sync title changes between editor and sidebar

Fix bug

style: change trash icon color to gray

docs: improve main README layout

docs: split README into English and Japanese versions

docs: update README with latest features and improvements

fix: resolve hydration issues by safely handling localStorage access

feat: implement real-time title sync between main content and sidebar

Add title editing and saving functionality

Fix Prism initialization and code block highlighting

Update README.md to reflect Article components

Remove old Todo-related files

Refactor Todo components to Article components

Update README with Japanese translations