Add some doc comments

src/index.ts

@@ -31,6 +31,9 @@ type Options = {
 };
 
 type Result = Summary & {
+	/**
+	 * The actual url of that web page
+	 */
 	url: string;
 };
 

src/summary.ts

@@ -1,8 +1,27 @@
 type Summary = {
+	/**
+	 * The description of that web page
+	 */
 	description: string;
+
+	/**
+	 * The url of the icon of that web page
+	 */
 	icon: string;
+
+	/**
+	 * The name of site of that web page
+	 */
 	sitename: string;
+
+	/**
+	 * The url of the thumbnail of that web page
+	 */
 	thumbnail: string;
+
+	/**
+	 * The title of that web page
+	 */
 	title: string;
 }