Update Main UI script editor docs (openhab#2232)

Signed-off-by: Florian Hotze <[email protected]>

mainui/settings/script-editor.md

@@ -9,10 +9,34 @@ title: Script Editor
 The script editor is used everywhere in the UI where some type of configuration file or source code has to be edited.
 It provides syntax highlighting and auto-completion for code and Item names for multiple languages.
 
-When using the script editor, you might find the following shortcuts useful:
+## Keyboard Shortcuts
+
+The following is a short overview of the most important keyboard shortcuts.
+For a full list of available keyboard shortcuts, read the [CodeMirror docs](https://codemirror.net/5/doc/manual.html#commands).
+
+Mac users should use <kbd>Cmd</kbd> instead of <kbd>Ctrl</kbd> for most shortcuts.
+
+Autocompletion & Help:
 
 - <kbd>Ctrl</kbd><kbd>Space</kbd>: Trigger auto-completion.
 - <kbd>Ctrl</kbd><kbd>Q</kbd>: Show documentation (for JavaScript only).
+
+Copy & Paste:
+
+- <kbd>Ctrl</kbd><kbd>C</kbd>: Copy the current line or the current selection.
+- <kbd>Ctrl</kbd><kbd>X</kbd>: Cut the current line or the current selection.
+- <kbd>Ctrl</kbd><kbd>V</kbd>: Paste what has been copied.
+
+Redo & Undo:
+
+- <kbd>Ctrl</kbd><kbd>Z</kbd>: Undo the last change.
+- <kbd>Ctrl</kbd><kbd>Y</kbd>: Redo the last change.
+
+Other:
+
+- <kbd>Tab</kbd>: Indent more.
 - <kbd>Shift</kbd><kbd>Tab</kbd>: Indent less.
-- <kbd>Ctrl</kbd><kbd>/</kbd> & <kbd>Cmd</kbd><kbd>/</kbd>: Comment/Uncomment the current line.
+- <kbd>Ctrl</kbd><kbd>D</kbd>: Delete the current line.
+- <kbd>Ctrl</kbd><kbd>/</kbd>: Comment/Uncomment the current line.
+- <kbd>Ctrl</kbd><kbd>A</kbd>: Select all.
 <!-- END MAINUI SIDEBAR DOC - DO NOT REMOVE -->