Keyboard usage

FreeDOSshell can be used with or without the mouse. Almost every button on
every window has an underlined character. The button can be used by pressing
the letter key of the underlined character.

Other keyboard shortcuts are listed below.

General:
- ALT+F4: Close window
- ALT+F3: Minimize window
- ALT+F2: Minimize all windows (show desktop)
- ALT+F5: Tile windows
- ALT+F6: Cascade windows
- ESC: Quit FreeDOSshell
- ALT+M: Window menu

Dialog windows:
- Enter: OK/YES
- ESC: NO/CANCEL
- F1: Help

Desktop:
- Arrow keys: Change icon selection
- Enter: Use selected icon

File manager:
- Arrow keys, PGUP, PGDN: Change file selection
- DEL: Delete file
- CTRL+C: Copy file
- CTRL+X: Cut file
- CTRL+V: Paste file
- ALT+T: Open command prompt to the current directory
- F5: Update file list

Text viewer:
- Arrow keys, PGUP, PGDN, HOME, END: Scroll
