src/vs/workbench/contrib/preferences/browser/preferencesEditor.ts/PreferencesEditor/createDeprecationWarning
class PreferencesEditor:	private createDeprecationWarning(): void {
		const warningIcon = DOM.$('span');
		warningIcon.className = SeverityIcon.className(Severity.Warning) + ' icon';
		const warningText = DOM.$('span', undefined, nls.localize('splitJsonRemoveWarning', "Note - this split JSON settings editor will be simplified after July."));
		const learnMore = DOM.$('span.learnMore-button.pointer', undefined, nls.localize('learnMore', "Learn More"));
		const clickHandler = (e: DOM.EventLike) => {
			DOM.EventHelper.stop(e, false);
			this.openerService.open('https://aka.ms/AAcwpin');
		};

		this._register(DOM.addDisposableListener(learnMore, DOM.EventType.CLICK, clickHandler));
		this._register(DOM.addDisposableListener(learnMore, DOM.EventType.KEY_DOWN, e => {
			const event = new StandardKeyboardEvent(e);
			if (event.equals(KeyCode.Space) || event.equals(KeyCode.Enter)) {
				clickHandler(e);
				event.preventDefault();
				event.stopPropagation();
			}
		}));
		const deprecationWarning = DOM.$('div.deprecation-warning', undefined, warningIcon, warningText, learnMore);
		DOM.append(this.headerContainer, deprecationWarning);
	}