Add MiniMax (OpenAI-compatible, 204K context) as a provider example in
config.example.toml and usage docs (EN/ZH), alongside existing providers
like SiliconFlow and Bedrock. This helps users discover and configure
MiniMax models (MiniMax-M2.5, MiniMax-M2.5-highspeed) with cc-connect.
Co-Authored-By: octo-patch <noreply@github.com>