docs: link the tide/ear explainers behind the index inputs

README.md

@@ -35,5 +35,16 @@ const out = ['day,country,bite_index,spots_scored'];
 for (const r of rows) { out.push(`${r.day},GLOBAL,${r.global},${r.n}`); for (const [c,v] of Object.entries(r.countries)) out.push(`${r.day},${c},${v},`); }
 ```
 
+What feeds the index, explained for humans:
+
+- Tide timing (the strongest single driver in coastal spots): [how to read tides
+  for fishing](https://fishradar.ai/learn/how-to-read-tides-for-fishing/), plus live
+  [NOAA tide tables for 51 US fishing spots](https://fishradar.ai/tides/)
+- [Incoming vs outgoing tide](https://fishradar.ai/learn/incoming-vs-outgoing-tide/) —
+  which half actually bites
+- The newest signal FishRadar ships: [FishRadar Ear](https://fishradar.ai/ear/),
+  on-device detection of the sounds fish actually make
+  ([do fish make sounds?](https://fishradar.ai/learn/do-fish-make-sounds/))
+
 Sibling datasets: [fishing-regulations](https://huggingface.co/datasets/Ali4333/fishing-regulations) ·
 [fish-species-catalog](https://huggingface.co/datasets/Ali4333/fish-species-catalog)