fix(ai): fix wrong AI command line argument (#692)

This commit ensure that the aiServiceRegistry flag is spelled correctly.

Author: rickstaa

ai/gateways/onchain.mdx

@@ -35,7 +35,7 @@ for more information. Here’s a summary of the key steps:
   <Step title="Launch the AI Gateway">
     Now launch your AI Gateway node. The process is similar to the **docker** or **binary** setup in the [previous section](/ai/gateways/start-gateway), but requires additional flags to enable on-chain functionality. Example:
 
-    - `-AIServiceRegistry`: Ensures that the Gateway is connected to the Livepeer AI network.
+    - `-aiServiceRegistry`: Ensures that the Gateway is connected to the Livepeer AI network.
     - `-network=arbitrum-one-mainnet`: Connects the AI Gateway to the Arbitrum Mainnet network.
     - `-ethUrl=https://arb1.arbitrum.io/rpc`: Sets the Arbitrum Mainnet RPC URL. Replace it with your own if necessary.
     - `-ethKeystorePath=/root/.lpData/arbitrum-one-mainnet/keystore`: Sets the path to the Ethereum keystore file for the AI Gateway.