Option to start new ingestion with depth 1

[gammazero]

To start ingesting only content published from the time an indexer is started, a new config option could be added to make the indexer behave this way.

For any new provider, only ingest the head of the ad chain (depth 1).

Is there a use case for this?

[masih]

Please update the description with the motivation for the idea. What problem does the idea solve?
Is this potentially a duplicate of #447 ?