feat(quick-260329-u1d): add kindgerechte Erklaerung on forest screen

- Added forest__intro paragraph between title and greeting area in index.html
- Added .forest__intro CSS block with Nunito font, centered, pastel-style styling

src/styles/main.css

@@ -187,6 +187,17 @@ h3 {
 	margin-bottom: 1.5rem;
 }
 
+.forest__intro {
+	font-family: "Nunito", sans-serif;
+	font-size: 1.1rem;
+	color: var(--text-dark);
+	text-align: center;
+	max-width: 480px;
+	line-height: 1.6;
+	margin: 0 auto 1.5rem;
+	opacity: 0.85;
+}
+
 .forest__level-map {
 	display: grid;
 	grid-template-columns: repeat(3, 1fr);