fix(jargon): link subnet to network-overview on first use in cycles costs

Author: marc0olo

docs/reference/cycles-costs.md

@@ -20,7 +20,7 @@ You can use the [pricing calculator](https://3d5wy-5aaaa-aaaag-qkhsq-cai.icp0.io
 
 ## Replication factors
 
-Costs scale with the number of nodes in the [subnet](subnet-types.md). The base cost tables below assume a **13-node application subnet**. For a 34-node (fiduciary) subnet, costs scale as `34 * (cost / 13)`:
+Costs scale with the number of nodes in the [subnet](../concepts/network-overview.md#subnets). The base cost tables below assume a **13-node application subnet**. For a 34-node (fiduciary) subnet, costs scale as `34 * (cost / 13)`:
 
 - **13-node subnet**: Standard application subnets. No scaling needed: costs are as listed.
 - **34-node subnet**: Fiduciary subnets (higher security for financial applications). Costs are approximately **2.6×** the 13-node cost.