add defaults in StoryShareParams and StoryWidgetLink

tgbotapi.webapps/src/jsMain/kotlin/dev/inmo/tgbotapi/webapps/stories/StoryShareParams.kt

@@ -10,7 +10,7 @@ external interface StoryShareParams {
 
 fun StoryShareParams(
     text: String,
-    widgetLink: StoryWidgetLink?
+    widgetLink: StoryWidgetLink? = null
 ): StoryShareParams {
     val json = json()
     json["text"] = text

tgbotapi.webapps/src/jsMain/kotlin/dev/inmo/tgbotapi/webapps/stories/StoryWidgetLink.kt

@@ -9,7 +9,7 @@ external interface StoryWidgetLink {
 
 fun StoryWidgetLink(
     url: String,
-    name: String?
+    name: String? = null
 ): StoryWidgetLink {
     val json = json()
     json["url"] = url