This is more helpful than anything I have ever encountered on the topic.
Comments:
1. It should explain map somewhere before it is used.
2. For the more abstruse and abstract concepts, a comment suggesting why anybody should care about this idea at all would be helpful. E.g., "A is just a name for what [familiar things] X, Y, and Z have in common."
3. It goes off the rails halfway through. E.g. Lift.
Expanding on your #1, I think they could use some more definitions. As you say, they use "map" in its functional programming sense before defining it, but I think more confusing is this one:
> A category in category theory is a collection of objects and morphisms between them.
What is a "morphism"?
I think this is a great starting point though, which could use some expansion.
Comments:
1. It should explain map somewhere before it is used.
2. For the more abstruse and abstract concepts, a comment suggesting why anybody should care about this idea at all would be helpful. E.g., "A is just a name for what [familiar things] X, Y, and Z have in common."
3. It goes off the rails halfway through. E.g. Lift.