Remove deploy docs readme badge (microsoft#449)

Description of changes

Since the deploy docs CD pipeline was removed in microsoft#436 it broke the deploy docs readme badge, so removing it here.

README.md

@@ -3,7 +3,6 @@
 [![NPM Version](https://img.shields.io/npm/v/@vscode/webview-ui-toolkit?color=blue)](https://www.npmjs.com/package/@vscode/webview-ui-toolkit)
 [![License: MIT](https://img.shields.io/badge/license-MIT-brightgreen)](./LICENSE)
 ![Toolkit CI Status](https://github.com/microsoft/vscode-webview-ui-toolkit/actions/workflows/ci.yml/badge.svg)
-![Deploy Docs Status](https://github.com/microsoft/vscode-webview-ui-toolkit/actions/workflows/docs-cd.yml/badge.svg)
 
 ![Webview Toolkit for Visual Studio Code Artwork](./docs/assets/images/toolkit-artwork.png)