docs: reuse the TEI parser in the house-format example, document unknown apiStyle

Author: TheGreatAxios

README.md

@@ -40,23 +40,25 @@ Config takes `baseURL` and `apiStyle`, with optional `model` (required by Cohere
 
 Jina's `/rerank` follows the Cohere shape and is served by the `cohere` adapter.
 
-To add a house format, build a registry with `createRerankAdapterRegistry` and pass it as `registry`:
+To add a house format, such as a TEI-shaped reply served at `/score`, build a registry with `createRerankAdapterRegistry` and pass it as `registry`:
 
 ```ts
 import {
   createRerankAdapterRegistry,
   rerankAdapterRegistry,
 } from "@corbits/reranking";
 
+const tei = rerankAdapterRegistry.resolve("tei");
+
 const registry = createRerankAdapterRegistry({
-  tei: rerankAdapterRegistry.resolve("tei"),
+  tei,
   house: {
     buildRequest: (query, docs, config) => ({
       url: `${config.baseURL}/score`,
       headers: { "content-type": "application/json" },
       body: JSON.stringify({ query, texts: docs.map((doc) => doc.text) }),
     }),
-    parseResponse: (body) => body as Array<{ index: number; score: number }>,
+    parseResponse: tei.parseResponse,
   },
 });
 ```
@@ -65,7 +67,7 @@ Providers reply with positions into the request array, so each score maps back t
 
 ## Errors
 
-Failures throw `RerankRequestError` (`extends Error`), carrying the classified `InferenceError` from `@intx/inference` as `reason` and the request `url`. That covers transport failures, HTTP errors, and replies in the wrong shape; retryable errors are retried first under the `retryPolicy` option, which defaults to `createDefaultRetryPolicy()`. An invalid config, including a missing `model` for Cohere or Voyage, throws arktype's `TraversalError` before any request is sent.
+Failures throw `RerankRequestError` (`extends Error`), carrying the classified `InferenceError` from `@intx/inference` as `reason` and the request `url`. That covers transport failures, HTTP errors, and replies in the wrong shape; retryable errors are retried first under the `retryPolicy` option, which defaults to `createDefaultRetryPolicy()`. An invalid config, including a missing `model` for Cohere or Voyage, throws arktype's `TraversalError` before any request is sent; an `apiStyle` the registry does not know throws a plain `Error` naming it.
 
 Fallback is left to the caller: catch the error and keep your own ordering if a reranker outage should not fail search.