Improve sendStory documentation.

td/generate/scheme/td_api.tl

@@ -9550,7 +9550,7 @@ canSendStory chat_id:int53 = CanSendStoryResult;
 //@caption Story caption; pass null to use an empty caption; 0-getOption("story_caption_length_max") characters; can have entities only if getOption("can_use_text_entities_in_story_caption")
 //@privacy_settings The privacy settings for the story; ignored for stories sent to supergroup and channel chats
 //@active_period Period after which the story is moved to archive, in seconds; must be one of 6 * 3600, 12 * 3600, 86400, or 2 * 86400 for Telegram Premium users, and 86400 otherwise
-//@from_story_full_id Full identifier of the original story, which content was used to create the story
+//@from_story_full_id Full identifier of the original story, which content was used to create the story; pass null if the story isn't repost of another story
 //@is_posted_to_chat_page Pass true to keep the story accessible after expiration
 //@protect_content Pass true if the content of the story must be protected from forwarding and screenshotting
 sendStory chat_id:int53 content:InputStoryContent areas:inputStoryAreas caption:formattedText privacy_settings:StoryPrivacySettings active_period:int32 from_story_full_id:storyFullId is_posted_to_chat_page:Bool protect_content:Bool = Story;