File-based Catalogs

[jchunkins]

Under section https://olm.operatorframework.io/docs/reference/file-based-catalogs/#olmcsvmetadata the docs indicate that there's a new property olm.csv.metadata but there is no description of the JSON contents at all. The relevant JSON data comes from the CSVMetadata struct (see https://github.com/operator-framework/operator-registry/blob/v1.36.0/alpha/property/property.go#L73-L88). Seems like the docs should define the expected content stored in this property.