Add TeamoRouter to Model Providers & Proxies

[takoyaki-baron]

Adds TeamoRouter to the Model Providers & Proxies section — a hosted OpenAI-compatible gateway that is directly relevant to the section intro (openai_base_url / any OpenAI-compatible API).

Codex fit:

• Native /v1/responses support — point Codex straight at https://api.teamorouter.cn/v1 with no local protocol conversion or proxy process
• Free daily tiers of DeepSeek V4 Pro (200 req/day) and V4 Flash (50 req/day, 1M context) for trying Codex without an OpenAI account
• The same key also serves Claude Code natively (Anthropic Messages protocol endpoint) — one provider for both CLIs

It is a hosted SaaS rather than a repo, so no star badge; the list already links non-repo resources (e.g. the Official Resources docs links), but happy to move it or drop it if you prefer repo-only entries here.

Config example (docs: https://teamorouter.cn/docs):

[model_providers.teamorouter]
name = "TeamoRouter"
base_url = "https://api.teamorouter.cn/v1"
env_key = "TEAMOROUTER_API_KEY"

Useful links:

• https://teamorouter.cn (landing page)
• https://teamorouter.cn/docs (API docs)
• https://developers.openai.com/codex/config-reference (upstream Codex config reference)