README feedback examples are silent no-ops — feedbackId is undocumented

Follow-up to #15 (thx for that fix — the loop does work now when driven via SearchOptions.feedbackId).

Problem: the README still teaches the old, broken pattern in all examples:

• L45: backend.recordFeedback(results[0].id, 0.9);
• L76: db.recordFeedback(hits[0].id, 1.0);

recordFeedback() looks up the trajectory by the feedbackId passed to searchAsync(q, k, { feedbackId }). A document id never matches, and the miss returns silently — so anyone coding from the README gets a no-op learning loop with no error. feedbackId currently appears nowhere in README or docs/ (grep on alpha.20).

Suggested:

1. Update the README examples to the feedbackId flow.
2. Document that recordFeedback() with an unknown id is ignored — or better, make that case throw/warn. A silent no-op on the headline feature is rough.

Also: #13 / #14 are fixed by #15 but still sitting open — they can be closed.

Start with the README examples at lines 45 and 76, then search docs/ for any existing feedback guidance. Update both examples to use the feedbackId flow from SearchOptions.feedbackId, and document how recordFeedback() behaves for an unknown id. Done means the README no longer passes document ids and the feedback behavior is stated clearly.