turn markdown cell into preview mode after hiding find.

src/vs/workbench/contrib/notebook/browser/contrib/find/findController.ts

@@ -362,6 +362,12 @@ export class NotebookFindWidget extends SimpleFindReplaceWidget implements INote
 			this._previousFocusElement.focus();
 			this._previousFocusElement = undefined;
 		}
+
+		this._notebookEditor.viewModel?.viewCells.forEach(cell => {
+			if (cell.getEditState() === CellEditState.Editing && cell.editStateSource === 'find') {
+				cell.updateEditState(CellEditState.Preview, 'find');
+			}
+		});
 	}
 
 	override _updateMatchesCount(): void {

src/vs/workbench/contrib/notebook/browser/notebookBrowser.ts

@@ -247,6 +247,7 @@ export interface ICellViewModel extends IGenericCellViewModel {
 	readonly layoutInfo: { totalHeight: number; };
 	readonly onDidChangeLayout: Event<{ totalHeight?: boolean | number; outerWidth?: number; }>;
 	readonly onDidChangeCellStatusBarItems: Event<void>;
+	readonly editStateSource: string;
 	dragging: boolean;
 	handle: number;
 	uri: URI;