mention marimo-lsp in readme (#115)

Author: akshayka

README.md

@@ -1,7 +1,8 @@
 # vscode marimo
 
 > [!Important]
-> **We are actively rewriting this extension to provide a more native and robust experience**, similar to what you may be used to when using Jupyter in VS Code. In the meantime, if you have issues with this extension, we recommend you run marimo from the terminal. See our [docs](https://docs.marimo.io/getting_started/) to get started.
+> **We are actively rewriting this extension to provide a more native and robust experience**, similar to what you may be used to when using Jupyter in VS Code. **The new extension is being developed in**
+> **[https://github.com/marimo-team/marimo-lsp](https://github.com/marimo-team/marimo-lsp), where new issues should be opened.** This repo is deprecated.
 
 <a href="https://marketplace.visualstudio.com/items?itemName=marimo-team.vscode-marimo" target="__blank">
   <img src="https://img.shields.io/visual-studio-marketplace/v/marimo-team.vscode-marimo.svg?color=eee&amp;label=VS%20Code%20Marketplace&logo=visual-studio-code" alt="Visual Studio Marketplace Version" />