Adding demo for video start position to the docs

website/more_documentation/video_documentation.py

@@ -1,6 +1,19 @@
 from nicegui import ui
+from website.documentation_tools import text_demo
 
 
 def main_demo() -> None:
     v = ui.video('https://test-videos.co.uk/vids/bigbuckbunny/mp4/h264/360/Big_Buck_Bunny_360_10s_1MB.mp4')
     v.on('ended', lambda _: ui.notify('Video playback completed'))
+
+
+def more() -> None:
+    @text_demo('Video start position', '''
+        This demo shows how to use javascript to set the start position of a video.
+    ''')
+    def advanced_usage() -> None:
+        async def set_time(_):
+            await ui.run_javascript(f'document.getElementById({v.id}).currentTime = 5;', respond=False)
+
+        v = ui.video('https://test-videos.co.uk/vids/bigbuckbunny/mp4/h264/360/Big_Buck_Bunny_360_10s_1MB.mp4')
+        v.on('loadedmetadata', set_time)