add network support note for alchemy_pendingtransactions (#71)

Author: SahilAujla

fern/api-reference/websockets/subscription-api-endpoints/alchemy-pendingtransactions.mdx

@@ -15,11 +15,7 @@ The `alchemy_pendingTransactions` subscription type subscribes to pending transa
 
 # Supported Networks
 
-<Info>
-  Check the [Chains](https://dashboard.alchemy.com/chains) page for details about product and chain support!
-
-  ![](523fb8a9a9d899921ee1046d0ff1b389967a9976d1c6112ebbbe071ddd1ef374-image.png)
-</Info>
+Please note that `alchemy_pendingTransactions` is only supported on **ETH Mainnet**, **ETH Sepolia** and **Matic Mainnet.**
 
 # Limits