Sneaky addition of the Hydra Synth (performance?)

src/API.ts

@@ -1455,6 +1455,17 @@ export class UserAPI {
       });
   };
 
+  // =============================================================
+  // Hydra integration
+  // =============================================================
+
+  stop_hydra = (): void => {
+    /**
+     * Empties the buffer of the Hydra sketch.
+     */
+    this.app.hydra.hush();
+  };
+
   // =============================================================
   // Trivial functions
   // =============================================================