Issues with keyboard shortcuts #15
Description
The help dialog is too long on small screens and does not scroll.
It should be possible to reset everything not only with a keyboard shortcut but also in the menu.
There should be hints about the keyboard shortcuts in the editor toolbar. Maybe in light grey beside the actual menu item or as a tooltip.
When pressing the keyboard shortcut for adding a node, it should be placed under the cursor.
There should also be a Ctrl+A shortcut for selecting all nodes.