Fix default timeout in GetTransactionReceiptAsync documentation

- Correct default timeout from 60 seconds to 3 minutes
- Update both comment and example code to reflect accurate default
- Addresses additional feedback from user review

Co-Authored-By: gleb@reown.com <gleb@skibitsky.com>

Author: devin-ai-integration[bot]

appkit/unity/core/actions.mdx

@@ -348,7 +348,7 @@ Debug.Log($"Block Hash: {receipt.BlockHash}");
 Debug.Log($"Status: {(receipt.StatusSuccessful ? "Success" : "Failed")}");
 Debug.Log($"Gas Used: {receipt.GasUsed}");
 
-// With custom timeout (default is 60 seconds)
+// With custom timeout (default is 3 minutes)
 TransactionReceipt receipt = await AppKit.EVM.GetTransactionReceiptAsync(
     "0x123...", // transaction hash
     TimeSpan.FromSeconds(120) // custom timeout
@@ -365,7 +365,7 @@ TransactionReceipt receipt = await AppKit.EVM.GetTransactionReceiptAsync(
 using var cts = new CancellationTokenSource();
 TransactionReceipt receipt = await AppKit.EVM.GetTransactionReceiptAsync(
     "0x123...", // transaction hash
-    TimeSpan.FromSeconds(60), // timeout
+    TimeSpan.FromMinutes(3), // timeout
     TimeSpan.FromSeconds(12), // polling interval
     cts.Token // cancellation token
 );