Sidebar more improvements
- While the sidebar is narrow, the searchbar will now appear on the center of the main page
- The Collapse/Expend sidebar button now has a shortcut. "Ctrl+Shift+1" which is based on the show/hide preview/editor ("Ctrl+Shift+9/8") but at the "opposite" side of the keyboard, which reflect the placement of those action's respective buttons.
- When creating a new note, it will be opened automatically