Update README with v9 announcement (#6193)

Author: nvuillam

README.md

@@ -54,9 +54,10 @@ MegaLinter has **native integrations** with many major CI/CD tools.
 
 ![MegaLinter Presentation GIF](https://github.com/oxsecurity/megalinter/blob/main/docs/assets/images/MegaLinter-banner-Medium.gif?raw=true)
 
-[**Upgrade to MegaLinter v8 :)**](https://github.com/oxsecurity/megalinter/issues/3913)
+[**Upgrade to MegaLinter v9 :)**](https://github.com/oxsecurity/megalinter/issues/6192):
 
-[![Upgrade to v8 Video](https://img.youtube.com/vi/vbx-ifa1oXE/0.jpg)](https://www.youtube.com/watch?v=vbx-ifa1oXE)
+- Use the new [LLM Advisor](https://megalinter.io/latest/llm-advisor/) that will tell you how to fix linters issues
+- Create your own [MegaLinter Custom Flavors](https://megalinter.io/latest/custom-flavors/) to improve performance 
 
 <!-- online-doc-start -->
 Before you go further, see the [**online documentation website, which offers much easier navigation than this README**](https://megalinter.io/)