Update Go example to use generic eth_sendBundle instead of deprecated API

Changes the Go example to demonstrate authentication with eth_sendBundle
instead of the deprecated flashbots_getUserStats method. Keeps the same
structure and authentication logic as the original example.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

Author: odysseus0

docs/flashbots-auction/quick-start.mdx

@@ -48,6 +48,7 @@ Next, you need a means to communicate with the Flashbots network. The Flashbots
   values={[
     { label: 'ethers.js', value: 'ethers.js', },
     { label: 'web3.py', value: 'web3.py' },
+    { label: 'go', value: 'go' },
 	{ label: 'rust', value: 'rust'},
   ]}
 >
@@ -100,6 +101,76 @@ ETH_ACCOUNT_SIGNATURE: LocalAccount = Account.from_key(os.environ.get("ETH_SIGNA
 flashbot(w3, ETH_ACCOUNT_SIGNATURE)
 ```
 
+</TabItem>
+<TabItem value="go">
+
+```go
+package main
+
+import (
+	"bytes"
+	"crypto/ecdsa"
+	"encoding/json"
+	"io/ioutil"
+	"net/http"
+	"time"
+
+	"github.com/ethereum/go-ethereum/accounts"
+	"github.com/ethereum/go-ethereum/common/hexutil"
+	"github.com/ethereum/go-ethereum/crypto"
+)
+
+const (
+	flashbotURL     = "https://relay.flashbots.net"
+	flashbotXHeader = "X-Flashbots-Signature"
+)
+
+var (
+	// authSigner is an Ethereum private key that does NOT store funds and is NOT your bot's primary key.
+	// This is an identifying key for signing payloads to establish reputation and whitelisting
+	privateKey, _ = crypto.HexToECDSA(
+		"2e19800fcbbf0abb7cf6d72ee7171f08943bc8e5c3568d1d7420e52136898154",
+	)
+)
+
+func flashbotHeader(signature []byte, privateKey *ecdsa.PrivateKey) string {
+	return crypto.PubkeyToAddress(privateKey.PublicKey).Hex() +
+		":" + hexutil.Encode(signature)
+}
+
+func main() {
+	// Example: create a Flashbots authenticated request
+	mevHTTPClient := &http.Client{
+		Timeout: time.Second * 3,
+	}
+
+	// Prepare your RPC request (e.g., eth_sendBundle, eth_callBundle, etc.)
+	params := map[string]interface{}{
+		"jsonrpc": "2.0",
+		"id":      1,
+		"method":  "eth_sendBundle", // or other Flashbots RPC methods
+		"params":  []interface{}{ /* your bundle params */ },
+	}
+
+	payload, _ := json.Marshal(params)
+	req, _ := http.NewRequest("POST", flashbotURL, bytes.NewBuffer(payload))
+
+	// Sign the payload for Flashbots authentication
+	headerReady, _ := crypto.Sign(
+		accounts.TextHash([]byte(hexutil.Encode(crypto.Keccak256(payload)))),
+		privateKey,
+	)
+
+	req.Header.Add("content-type", "application/json")
+	req.Header.Add("Accept", "application/json")
+	req.Header.Add(flashbotXHeader, flashbotHeader(headerReady, privateKey))
+
+	resp, _ := mevHTTPClient.Do(req)
+	res, _ := ioutil.ReadAll(resp.Body)
+	_ = res // process response
+}
+```
+
 </TabItem>
 <TabItem value="rust">