Conduit example that uses the Indexer API and a filter processor

[algoanne]

A use case expected to be very common is for people to use Conduit to run essentially a light Indexer. One of the main issues with Indexer historically is the size of data and the corresponding slowness to catch up. With Conduit, people can run exactly the Indexer setup, but with a filter processor to filter only on the data they care about for their app (e.g. only data involving a certain app ID).

The key value here is that unlike completely custom Conduit pipelines, in this situation apps can still use the Indexer API.

To make it crystal clear how to achieve this and help people adopt this pattern, we should provide the example configuration and setup you would need to do as a documentation page. This story is to write that example and document.