docs: improve README with contributors section, badges, and community links

[anurag629]

Summary

The root README is missing a contributors section and some standard open-source README elements. Adding these makes the project more welcoming and gives credit to people who contribute.

What to add

1. Badges at the top

Add status badges after the heading (# ChatCops):

[![CI](https://github.com/codercops/chatcops/actions/workflows/ci.yml/badge.svg)](https://github.com/codercops/chatcops/actions/workflows/ci.yml)
[![npm @chatcops/widget](https://img.shields.io/npm/v/@chatcops/widget?label=widget)](https://www.npmjs.com/package/@chatcops/widget)
[![npm @chatcops/core](https://img.shields.io/npm/v/@chatcops/core?label=core)](https://www.npmjs.com/package/@chatcops/core)
[![npm @chatcops/server](https://img.shields.io/npm/v/@chatcops/server?label=server)](https://www.npmjs.com/package/@chatcops/server)
[![License: MIT](https://img.shields.io/badge/License-MIT-yellow.svg)](./LICENSE)

2. Contributors section

Add a contributors section before the License section using auto-generated avatars:

## Contributors

<a href="https://github.com/codercops/chatcops/graphs/contributors">
  <img src="https://contrib.rocks/image?repo=codercops/chatcops" />
</a>

This auto-generates contributor avatars from GitHub and stays up to date — zero maintenance.

3. Community / Links section

Add links to help people find their way:

## Links

- [Documentation](https://chat.codercops.com)
- [Contributing Guide](./CONTRIBUTING.md)
- [Report a Bug](https://github.com/codercops/chatcops/issues/new)
- [CoderCops](https://codercops.com)

Files to modify

File	Change
README.md	Add badges, contributors section, and links

Acceptance Criteria

• CI and npm version badges visible at the top
• Contributors section present with auto-generated avatars
• Links section with docs, contributing guide, and bug report links
• Existing README content unchanged — only additions