added wotw links for Baseline and GestureDetector (#99178)

packages/flutter/lib/src/widgets/basic.dart

@@ -3359,6 +3359,8 @@ class IntrinsicHeight extends SingleChildRenderObjectWidget {
 /// the top of the child to the baseline of the child, then the child
 /// is top-aligned instead.
 ///
+/// {@youtube 560 315 https://www.youtube.com/watch?v=8ZaFk0yvNlI}
+///
 /// See also:
 ///
 ///  * [Align], a widget that aligns its child within itself and optionally

packages/flutter/lib/src/widgets/gesture_detector.dart

@@ -171,6 +171,8 @@ class GestureDetector extends StatelessWidget {
   /// because a combination of a horizontal and vertical drag is a pan. Simply
   /// use the pan callbacks instead.
   ///
+  /// {@youtube 560 315 https://www.youtube.com/watch?v=WhVXkCFPmK4}
+  ///
   /// By default, gesture detectors contribute semantic information to the tree
   /// that is used by assistive technology.
   GestureDetector({