The code samples used to demonstrate that library loads a trees.geojson file with features like 'oak' and 'maple', so I think he definitely meant 'topography'. What makes you say it's a topology library?
See the authors comment above. The library does do a lot more than topology, but the see the sections titled: joins, measurement and transformation. These are all topological functions.
> "Topology ignores such things as corners, distances, and convexity."
No, that's what topology is.
> "That makes it hard to combine with GIS systems."
No, GIS systems rely heavily on topology. Here are two definitions:
Topology: 1. the study of geometric properties and spatial relations unaffected by the continuous change of shape or size of figures.
Topography: 1. the arrangement of the natural and artificial physical features of an area.