Use cmd+\ to split terminal

Part of #7504

src/vs/workbench/parts/terminal/electron-browser/terminal.contribution.ts

@@ -417,9 +417,10 @@ actionRegistry.registerWorkbenchAction(new SyncActionDescriptor(MoveToLineEndTer
 	mac: { primary: KeyMod.CtrlCmd | KeyCode.RightArrow }
 }, KEYBINDING_CONTEXT_TERMINAL_FOCUS), 'Terminal: Move To Line End', category);
 actionRegistry.registerWorkbenchAction(new SyncActionDescriptor(SplitTerminalAction, SplitTerminalAction.ID, SplitTerminalAction.LABEL, {
-	primary: KeyMod.CtrlCmd | KeyMod.Shift | KeyCode.KEY_5,
+	primary: KeyMod.CtrlCmd | KeyCode.US_BACKSLASH,
+	secondary: [KeyMod.CtrlCmd | KeyMod.Shift | KeyCode.KEY_5],
 	mac: {
-		primary: KeyMod.CtrlCmd | KeyCode.KEY_D,
+		primary: KeyMod.CtrlCmd | KeyCode.US_BACKSLASH,
 		secondary: [KeyMod.CtrlCmd | KeyMod.Shift | KeyCode.KEY_5]
 	}
 }, KEYBINDING_CONTEXT_TERMINAL_FOCUS), 'Terminal: Split', category);