🚀 Integration: Add tRPC-Agent-Go Support (1st Party, Supported)

I'd like to contribute a documentation update to list [tRPC-Agent-Go](https://github.com/trpc-group/trpc-agent-go) as an AG-UI compatible agent framework (Community, 🛠️ In Progress) in the “Supported Integrations” tables.

Framework:
- Name: tRPC-Agent-Go
- Repo: https://github.com/trpc-group/trpc-agent-go
- Contact/Maintainer: @Flash-LHR

AG-UI integration details (external docs/examples):
- AG-UI guide: https://trpc-group.github.io/trpc-agent-go/agui/
- Examples: https://github.com/trpc-group/trpc-agent-go/tree/main/examples/agui

Proposed changes:
1) README.md -> Supported Integrations -> Frameworks -> Community
Add a new row for tRPC-Agent-Go with status 🛠️ In Progress.

2) docs/introduction.mdx -> Supported Integrations -> Agent Framework - Community
Add the same row there as well to keep the Docs page consistent with the README.