docs(amazonq): update README.md to point to new Amazon Q VS Code extension link (#6859)

## Problem
The README.md file link to the Amazon Q VS Code extension in the
marketplace was outdated.

## Solution
Updated link to point to correct extension.

---

- Treat all work as PUBLIC. Private `feature/x` branches will not be
squash-merged at release time.
- Your code changes must meet the guidelines in
[CONTRIBUTING.md](https://github.com/aws/aws-toolkit-vscode/blob/master/CONTRIBUTING.md#guidelines).
- License: I confirm that my contribution is made under the terms of the
Apache 2.0 license.

Co-authored-by: Ritik Khatwani <[email protected]>

Author: ritikk

README.md

@@ -9,7 +9,7 @@ any positive contribution. See [CONTRIBUTING.md](CONTRIBUTING.md) to get started
 
 [![Marketplace Version](https://img.shields.io/vscode-marketplace/v/AmazonWebServices.amazon-q-vscode.svg) ![Marketplace Downloads](https://img.shields.io/vscode-marketplace/d/AmazonWebServices.amazon-q-vscode.svg)](https://marketplace.visualstudio.com/items?itemName=AmazonWebServices.amazon-q-vscode)
 
-Amazon Q for VS Code is a [VS Code extension](https://marketplace.visualstudio.com/itemdetails?itemName=AmazonWebServices.aws-toolkit-vscode) for connecting your IDE to [Amazon Q](https://aws.amazon.com/q/developer/) and leveraging generative AI to accelerate your software development.
+Amazon Q for VS Code is a [VS Code extension](https://marketplace.visualstudio.com/items?itemName=AmazonWebServices.amazon-q-vscode) for connecting your IDE to [Amazon Q](https://aws.amazon.com/q/developer/) and leveraging generative AI to accelerate your software development.
 
 -   Code faster with inline code suggestions as you type
 -   Chat with [Amazon Q](https://aws.amazon.com/q/developer/) to generate code, explain code, and get answers to questions about software development