Decorators page refers to inexistent example

[nyibbang]

Hello,

In the page about Decorators, in the section about ConsumeQueue there is a link that refers to an inexistent example file named ex04_waypoints.cpp.

btcpp_website/docs/nodes-library/DecoratorNode.md

Line 83 in a63ca21

Register for example with `factory.registerNodeType<ConsumeQueue<Pose2D>>("ConsumeQueue");` Cf. [ex04_waypoints.cpp](https://github.com/BehaviorTree/BehaviorTree.CPP/blob/master/examples/ex04_waypoints.cpp).

I believe the example file should be t18_waypoints.cpp instead.

On a side note, the ConsumeQueue is marked as deprecated in the library, and the use of LoopNode is encouraged instead.