Update video link

(cherry picked from commit 92737c6)

Author: deliahu

README.md

@@ -2,7 +2,7 @@
 
 <br>
 
-**Get started:** [Install](https://docs.cortex.dev/install) • [Tutorial](https://docs.cortex.dev/tutorial) • [Demo Video](https://www.youtube.com/watch?v=vcistUor0b4) • <!-- CORTEX_VERSION_MINOR_STABLE e.g. https://docs.cortex.dev/v/0.2/ -->[Docs](https://docs.cortex.dev/v/0.4) • <!-- CORTEX_VERSION_MINOR_STABLE -->[Examples](https://github.com/cortexlabs/cortex/tree/0.4/examples)
+**Get started:** [Install](https://docs.cortex.dev/install) • [Tutorial](https://docs.cortex.dev/tutorial) • [Demo Video](https://www.youtube.com/watch?v=tgMjCOD_ufo) • <!-- CORTEX_VERSION_MINOR_STABLE e.g. https://docs.cortex.dev/v/0.2/ -->[Docs](https://docs.cortex.dev/v/0.4) • <!-- CORTEX_VERSION_MINOR_STABLE -->[Examples](https://github.com/cortexlabs/cortex/tree/0.4/examples)
 
 **Learn more:** [Website](https://cortex.dev) • [FAQ](https://docs.cortex.dev/faq) • [Blog](https://blog.cortex.dev) • [Subscribe](https://cortexlabs.us20.list-manage.com/subscribe?u=a1987373ab814f20961fd90b4&id=ae83491e1c) • [Twitter](https://twitter.com/cortex_deploy) • [Contact](mailto:hello@cortex.dev)