fix(docs): Updated Discord Badge in README for Better Visibility (#10360)

### Motivation 💡

The previous Discord badge in the README used `dcbadge.vercel.app`,
which often fails to render correctly and displays an invalid or broken
badge.

### Changes 🛠️

- Replaced the broken badge with a `shields.io` Discord badge that is
visually consistent with the Twitter badge
- Ensures clearer visual guidance and a more professional appearance

### Notes ✏️

This PR only updates the `README.md` no frontend, backend, or
configuration files are touched. This change improves the aesthetics and
onboarding experience for new contributors.

Screenshot of the issue:
<img width="405" height="47" alt="Screenshot 2025-07-12 175316"
src="https://github.com/user-attachments/assets/41f7355c-f795-4163-855f-3d01f2478dd7"
/>

---------

Co-authored-by: Ubbe <hi@ubbe.dev>
Co-authored-by: Bently <Github@bentlybro.com>
Co-authored-by: Bently <tomnoon9@gmail.com>

README.md

@@ -1,7 +1,7 @@
 # AutoGPT: Build, Deploy, and Run AI Agents
 
-[![Discord Follow](https://dcbadge.vercel.app/api/server/autogpt?style=flat)](https://discord.gg/autogpt)  
-[![Twitter Follow](https://img.shields.io/twitter/follow/Auto_GPT?style=social)](https://twitter.com/Auto_GPT)
+[![Discord Follow](https://img.shields.io/badge/dynamic/json?url=https%3A%2F%2Fdiscord.com%2Fapi%2Finvites%2Fautogpt%3Fwith_counts%3Dtrue&query=%24.approximate_member_count&label=total%20members&logo=discord&logoColor=white&color=7289da)](https://discord.gg/autogpt)  
+[![Twitter Follow](https://img.shields.io/twitter/follow/Auto_GPT?style=social)](https://twitter.com/Auto_GPT)  
 
 **AutoGPT** is a powerful platform that allows you to create, deploy, and manage continuous AI agents that automate complex workflows.