Controls:
- Middle mouse: Move canvas
- Right click: New card
- Left click & drag: Move card
- Mouse wheel: Zoom
- Ctrl/Alt + wheel: Scroll
- Delete: Remove card
- Z: Reset view
- Shift + click: Connect cards
- E: Export | I: Import JSON
- ESC: Exit editing
- Strg + s: Manuell save
- Strg + L: Load manuell save