[skip e2e] Add comments to conf adapter file (#14509)

Signed-off-by: jingkl <jingjing.jia@zilliz.com>

internal/util/indexparamcheck/conf_adapter_test.go

@@ -65,6 +65,7 @@ func TestBaseConfAdapter_CheckTrain(t *testing.T) {
 	}
 }
 
+// IVFConfAdapter checks if an ivf index can be built.
 func TestIVFConfAdapter_CheckTrain(t *testing.T) {
 	validParams := map[string]string{
 		DIM:    strconv.Itoa(128),