add alibabacloud opensearch mcp server in README

[bestCMC]

Description

Add official Alibaba Cloud OpenSearch MCP server (https://github.com/aliyun/alibabacloud-opensearch-mcp-server) on Official integrations section.

Server Details

• Server: Alibaba Cloud OpenSearch MCP server
• Changes to: Adding a new server entry to the README.md

Motivation and Context

This MCP server equips AI Agents with tools to interact with OpenSearch through a standardized and extensible interface.

How Has This Been Tested?

Integration with the server was tested from cline.

Breaking Changes

N/A

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation update

Checklist

• I have read the MCP Protocol Documentation
• My changes follows MCP security best practices
• I have updated the server's README accordingly
• I have tested this with an LLM client
• My code follows the repository's style guidelines
• New and existing tests pass locally
• I have added appropriate error handling
• I have documented all environment variables and configuration options

Additional context