Explain originId (flashbots#563)

Author: sketsdever

docs/flashbots-protect/quick-start.mdx

@@ -24,6 +24,10 @@ Fast mode details:
 
 **Note**: When you send your transaction to a builder, you trust them not to frontrun your transaction or disclose it to third-party MEV searchers.
 
+### Customer Support
+
+Wallets and applications can receive customer support for transactions tagged with their `originId`. To opt into customer support update your RPC URL to `rpc.flashbots.net/fast?originId=[your-wallet-name]`.
+
 :::warning Do Not Switch RPCs Before Transaction Confirmation If you submit a transaction through Flashbots Protect via the MetaMask wallet, do not switch RPCs before transaction confirmation. MetaMask may resend the transaction to the public mempool exposing your transaction to potential MEV attacks if RPCs are switched before transaction confirmation.
 
 :::