Fix image path for demo video in README

Author: FrancescoSaverioZuppichini

README.md

@@ -5,7 +5,7 @@ Made with love by the [ScrapeGraphAI team](https://scrapegraphai.com) 💜
 
 ![Demo](./assets/demo.gif)
 
-![Demo Video](assets/demo.mp4)
+![Demo Video](./assets/demo.mp4)
 
 Command-line interface for [ScrapeGraph AI](https://scrapegraphai.com) — AI-powered web scraping, data extraction, search, and crawling.