Fix typo in Text docs (#18635)

diff --git a/packages/flutter/lib/src/widgets/text.dart b/packages/flutter/lib/src/widgets/text.dart
index 94fa551..f3a0c77 100644
--- a/packages/flutter/lib/src/widgets/text.dart
+++ b/packages/flutter/lib/src/widgets/text.dart
@@ -164,7 +164,7 @@
 /// for example, to make the text bold while using the default font family and
 /// size.
 ///
-/// Using the [new TextSpan.rich] constructor, the [Text] widget can also be
+/// Using the [new Text.rich] constructor, the [Text] widget can also be
 /// created with a [TextSpan] to display text that use multiple styles
 /// (e.g., a paragraph with some bold words).
 ///