README: simplify PK-convention step wording

README.md

@@ -64,7 +64,7 @@ One pipeline for all three benchmarks:
 
 - **Spider / BIRD**: released gold SQL + schema → **o4-mini** extracts used columns →
   post-processing: gold ⊆ schema (0 invalid) → no empty gold set → parser cross-check →
-  `COUNT(*)`/`SELECT *`-only tables represented by their PK → per-instance audit.
+  PK convention for star-only tables → per-instance audit.
 - **Spider 2.0 (Lite / Snow)**: shard-table grouping (`events_20201101`, … → `events_*`) →
   same steps as above.