periodicNoopIntervalSecs is used to configure interval of noop writes on the node.
SERVER-31132
https://github.com/mongodb/mongo/blob/90e078c73d49da75dd061005efc607c4e2721ae9/src/mongo/db/repl/replication_coordinator_impl.idl#L59-L68

We often get support cases about change stream latency on sharded clusters when some of the shards have low traffic. This latency is constrained by the slowest write rate across all shards and config server. On the config server noop is written every 1s, but on shards default is 10s. Users can change periodicNoopIntervalSecs to the minimum of 1s. Atlas users need help from TS to do it

1) Add it to the server parameters https://www.mongodb.com/docs/manual/reference/parameters
2) In the 2nd paragraph, we discuss Change Streams in shared clusters.
https://www.mongodb.com/docs/manual/administration/change-streams-production-recommendations/#sharded-clusters
Add here info that tuning periodicNoopIntervalSecs can bring latency down to about 1s.