Fix Mercury Link (#1602)

Author: briwylde08

docs/data/indexers/indexer-providers/indexer-providers.mdx

@@ -11,7 +11,7 @@ To power your applications, a range of data services will be available from data
 
 A data pipeline tool allowing you to combine on-chain and off-chain data however you like, streamed directly into your own custom database.
 
-### [Mercury](https://mercurydata.app/)
+### [Mercury](https://docs.mercurydata.app)
 
 A network indexing service that provides a toolkit to help get you started working with Stellar network data.