Please document how to import intersections and query them

Hello, I am actively trying to import an intersection layer into pelias to query.
Per documentation you can query with
http://10.11.34.81:4000/v1/search?layers=intersection&size=1&text=London

But I get
{"geocoding":{"version":"0.2","attribution":"http://10.11.34.81:4000/attribution","query":{"text":"London","size":1,"private":false,"lang":{"name":"English","iso6391":"en","iso6393":"eng","via":"header","defaulted":false},"querySize":20,"parser":"pelias","parsed_text":{"subject":"London","locality":"London"}},"errors":["'intersection' is an invalid layers parameter. Valid options: coarse,address,street,postalcode,locality,neighbourhood,localadmin,county,region,macrohood,borough,country,dependency"],"engine":{"name":"Pelias","author":"Mapzen","version":"1.0"},"timestamp":1644613839421},"type":"FeatureCollection","features":[]}

Which is reflective of me not having the layer or building it?

Please document a workflow for adding in intersection data and querying.

Use the issue's reported invalid-layers response and requested import workflow as the starting point. Review the existing Pelias documentation structure to find where layer-import and query guidance belongs, then document the prerequisites, import steps, and intersection query workflow; done means a reader can follow the workflow and understand the reported error.