Desktop: Add "duplicate line" command in Markdown editor (#4873)

Ref: https://discourse.joplinapp.org/t/duplicate-line-command/12650/15

packages/app-desktop/gui/MenuBar.tsx

@@ -596,6 +596,7 @@ function useMenu(props: Props) {
 						menuItemDic.attachFile,
 						separator(),
 						menuItemDic['editor.deleteLine'],
+						menuItemDic['editor.duplicateLine'],
 						menuItemDic['editor.toggleComment'],
 						menuItemDic['editor.sortSelectedLines'],
 						menuItemDic['editor.indentLess'],

packages/app-desktop/gui/NoteEditor/commands/editorCommandDeclarations.ts

@@ -87,6 +87,10 @@ const declarations: CommandDeclaration[] = [
 		name: 'editor.deleteLine',
 		label: () => _('Delete line'),
 	},
+	{
+		name: 'editor.duplicateLine',
+		label: () => _('Duplicate line'),
+	},
 	{
 		name: 'editor.undo',
 		label: () => _('Undo'),

packages/app-desktop/gui/menuCommandNames.ts

@@ -35,6 +35,7 @@ export default function() {
 		'toggleSideBar',
 		'toggleVisiblePanes',
 		'editor.deleteLine',
+		'editor.duplicateLine',
 		'editor.undo',
 		'editor.redo',
 		'editor.indentLess',

packages/lib/services/KeymapService.ts

@@ -46,6 +46,7 @@ const defaultKeymapItems = {
 		{ accelerator: 'Shift+Cmd+P', command: 'commandPalette' },
 		{ accelerator: 'F1', command: 'help' },
 		{ accelerator: 'Cmd+D', command: 'editor.deleteLine' },
+		{ accelerator: 'Shift+Cmd+D', command: 'editor.duplicateLine' },
 		{ accelerator: 'Cmd+Z', command: 'editor.undo' },
 		{ accelerator: 'Cmd+Y', command: 'editor.redo' },
 		{ accelerator: 'Cmd+[', command: 'editor.indentLess' },
@@ -87,6 +88,7 @@ const defaultKeymapItems = {
 		{ accelerator: 'Ctrl+Shift+P', command: 'commandPalette' },
 		{ accelerator: 'F1', command: 'help' },
 		{ accelerator: 'Ctrl+D', command: 'editor.deleteLine' },
+		{ accelerator: 'Shift+Ctrl+D', command: 'editor.duplicateLine' },
 		{ accelerator: 'Ctrl+Z', command: 'editor.undo' },
 		{ accelerator: 'Ctrl+Y', command: 'editor.redo' },
 		{ accelerator: 'Ctrl+[', command: 'editor.indentLess' },