add BlockMaterial.hitSound

src/content/ContentLoader.cpp

@@ -573,6 +573,10 @@ void ContentLoader::loadBlockMaterial(
     root.at("steps-sound").get(def.stepsSound);
     root.at("place-sound").get(def.placeSound);
     root.at("break-sound").get(def.breakSound);
+    root.at("hit-sound").get(def.hitSound);
+    if (def.hitSound.empty()) {
+        def.hitSound = def.stepsSound;
+    }
 }
 
 void ContentLoader::loadContent(const dv::value& root) {