chore: Add issue number in TODO comment

src/operator/MetaOperatorDefs/Leaky.cpp

@@ -57,7 +57,7 @@ std::shared_ptr<Node> Leaky(const int nbTimeSteps,
                        /*outId=*/memorizeOpDataOutputRecIndex,
                        /*otherInId=*/0);
 
-    // TODO: Handle hard/soft reset
+    // TODO(#219) Handle hard/soft reset
     uth->addChild(reset, 0, 1);
 
     // Input[T] + beta * U[T-1] - S[T-1] * U_th