Clearer guidance on adding multiple layers #94
Description
Great work Tim et al with OL and this important learning resource (esp. since exising OL3 books are becoming less useful).
Please consider that there maybe a need for clearer guidance on how to add multiple layers to a map object. From my limited OL experience, I think there are at least four ways that this is done in existing resources (various books, OL examples, workshop, API docs etc). As a new OL user I find this confusing.
My suggestion is that you include how to add multiple layers in the workshop examples/code. I appreciate there may be different use cases for adding layers in different ways. I also appreciate there are multiple types of layers.