Doc: Update README.md to include OceanBase MCP server to official integrations section

[yuanoOo]

Description

Add OceanBase to list of Official Integrations 3rd party integrations

Server Details

• Server: Adds https://github.com/oceanbase/mcp-oceanbase

Motivation and Context

OceanBase is an enterprise-level open source distributed relational database with high availability, high performance, horizontal scalability, and compatibility with SQL standards.
This helps users find OceanBase mcp server.

How Has This Been Tested?

This has been tested with Claude Desktop application and there are also some automated tests in the repo.

Breaking Changes

None

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

[yuanoOo]

@tadasant PTAL.