Update build-parachains.md - coretime marketplaces (#5881)

Add relevant links

docs/build/build-parachains.md

@@ -383,10 +383,9 @@ are available.
 To include your parachain into the {{ polkadot: Polkadot :polkadot }}{{ kusama: Kusama :kusama }}
 network, you will need to acquire a parachain slot.
 
-Parachain slots will be sold in open auctions, the mechanics of which can be found on the
-[parachain auction](../learn/learn-auction.md) page.
-
-A parachain can be producing blocks 
+Parachain slot leases are acuqired through open auctions, the mechanics of which can be found on the
+[parachain auction](../learn/learn-auction.md) page. With [Agile Coretime,](../learn/learn-agile-coretime.md)
+these parachain lease auctions will be deprecated and parachains can [purchase coretime](../learn/learn-guides-coretime-marketplaces.md) to produce blocks 
 [continuously or on-demand](../learn/learn-parachains.md#parachains-vs-on-demand-parachains).
 
 ## Resources