Update app.py

app.py

@@ -8,13 +8,15 @@ class YouTubeDownloader:
         url = st.text_input("Enter YouTube URL to download:")
         if url:
             YouTubeDownloader.validate_url(url)
-            with st.expander("Preview video"):
+            with st.expander("preview video"):
                 st.video(url)
             if st.button("Download"):
                 YouTubeDownloader.cleanup()
                 file_ = YouTubeDownloader.download_video(url)
                 st.video(file_)
                 YouTubeDownloader.helper_message()
+        st.markdown("> App made by Abhay Koul ([HelpingAI on GitHub](https://github.com/HelpingAI))")
+
 
     @staticmethod
     def download_video(url):
@@ -48,9 +50,10 @@ class YouTubeDownloader:
     @classmethod
     def helper_message(cls):
         st.write(
-            "> To save the video to the local computer, "
+            "> To save the video to local computer, "
             "click the vertical ... icon (aka hamburger button) in the bottom-right corner (in the video above) and click download."
         )
 
+
 if __name__ == "__main__":
-    YouTubeDownloader.run()
+    YouTubeDownloader.run()