update docstring of the delete bookmark callback

Author: shtlrs

bot/exts/utilities/bookmark.py

@@ -115,10 +115,9 @@ async def _delete_bookmark_context_menu_callback(
         message: discord.Message,
     ) -> None:
         """
-        Delete the Sir-Lancebot message that the command invocation is replying to.
+        The callback that will be invoked upon using the "Delete Bookmark" context menu command.
 
-        This command allows deleting any message sent by Sir-Lancebot in the user's DM channel with the bot.
-        The command invocation must be a reply to the message that is to be deleted.
+        This contains all the logic when it comes to deleting Sir-Lancebot's bookmark DM messages.
         """
         if interaction.channel.type != discord.ChannelType.private:
             raise commands.UserInputError("You can only run this command your own DMs!")