Missing documentation for cbc-pillowfight - using user generated documents

cbc-pillowfight has the option to use user created documents instead of randomly generated documents using the '-docs' flag:

https://github.com/couchbase/libcouchbase/blob/master/tools/cbc-pillowfight.cc#L130C1-L131C1

This feature is not documented or mentioned in any way in our documentation:

https://docs.couchbase.com/sdk-api/couchbase-c-client/md_doc_cbc_pillowfight.html

Please add documentation with the required syntax and exact behavior when this feature is used.