Add Things3 MCP server to official integrations list

- Added Things3 MCP server for comprehensive Things3 task management integration on macOS
- Positioned alphabetically between Thirdweb and Tianji
- Provides 25 specialized tools for TODOs, projects, areas, tags, and bulk operations

Author: urbanogardun

README.md

@@ -189,6 +189,7 @@ Official integrations are maintained by companies building production ready MCP
 - <img height="12" width="12" src="https://tavily.com/favicon.ico" alt="Tavily Logo" /> **[Tavily](https://github.com/tavily-ai/tavily-mcp)** - Search engine for AI agents (search + extract) powered by [Tavily](https://tavily.com/)
 - <img height="12" width="12" src="https://raw.githubusercontent.com/hashicorp/terraform-mcp-server/main/public/images/Terraform-LogoMark_onDark.svg" alt="Terraform Logo" /> **[Terraform](https://github.com/hashicorp/terraform-mcp-server)** - Seamlessly integrate with Terraform ecosystem, enabling advanced automation and interaction capabilities for Infrastructure as Code (IaC) development powered by [Terraform](https://www.hashicorp.com/en/products/terraform)
 - <img height="12" width="12" src="https://thirdweb.com/favicon.ico" alt="Thirdweb Logo" /> **[Thirdweb](https://github.com/thirdweb-dev/ai/tree/main/python/thirdweb-mcp)** - Read/write to over 2k blockchains, enabling data querying, contract analysis/deployment, and transaction execution, powered by [Thirdweb](https://thirdweb.com/)
+- **[Things3 MCP](https://github.com/urbanogardun/things3-mcp)** - Things3 task management integration for macOS with comprehensive TODO, project, and tag management.
 - <img height="12" width="12" src="https://tianji.msgbyte.com/img/dark-brand.svg" alt="Tianji Logo" /> **[Tianji](https://github.com/msgbyte/tianji/tree/master/apps/mcp-server)** - Interact with Tianji platform whatever selfhosted or cloud platform, powered by [Tianji](https://tianji.msgbyte.com/).
 - <img height="12" width="12" src="https://www.pingcap.com/favicon.ico" alt="TiDB Logo" /> **[TiDB](https://github.com/pingcap/pytidb)** - MCP Server to interact with TiDB database platform.
 - <img height="12" width="12" src="https://www.tinybird.co/favicon.ico" alt="Tinybird Logo" /> **[Tinybird](https://github.com/tinybirdco/mcp-tinybird)** - Interact with Tinybird serverless ClickHouse platform