What does croct install actually do, and why a postinstall hook?

I ran the Croct CLI and noticed that croct install registered a postinstall hook in the project. Anything that hooks into the install step gets scrutiny from me before it goes near our pipeline, so I want to understand exactly what it does before I let it run in CI.

Is the hook actually needed, or is it a convenience? And what does it generate when it fires? I would rather know what it touches than find out from a diff.