feat: add util package for generating search indices (#8571)

packages/api-extractor-utils/src/tsdoc/PlainTextCommentNode.ts

@@ -0,0 +1,13 @@
+import type { DocPlainText } from '@microsoft/tsdoc';
+import { type DocNodeJSON, node } from './CommentNode';
+
+export interface DocPlainTextJSON extends DocNodeJSON {
+	text: string;
+}
+
+export function plainTextNode(plainTextNode: DocPlainText): DocPlainTextJSON {
+	return {
+		...node(plainTextNode),
+		text: plainTextNode.text,
+	};
+}