This is a Valve made resource for the modding community.

If you open up the map in Hammer (it's saved in [Steam Library Folder]\Half-Life Alyx\content\hlvr\maps\workshop_examples), you will see detailed text explaining how the encounter works, alongside tips on making the navmesh work.

You may also notice 3 other maps, labeled Cables, Hotspot, and Tilemesh. Look into those maps as well, they give info on some of the new stuff that Source 2's Hammer has to offer.