v1.3.7: add hard_negatives_n300 trap set (N=300)

extensions/extension_manifest.json

@@ -16,5 +16,10 @@
     "n": 300,
     "json": "split_pattern_custom_n300.json",
     "csv": "split_pattern_custom_n300.csv"
+  },
+  "hard_negatives_n300": {
+    "n": 300,
+    "json": "hard_negatives_n300.json",
+    "csv": "hard_negatives_n300.csv"
   }
 }