Proposer alert private key danger

packages/website/pages/docs/guides/enable-a-proposer.mdx

@@ -25,12 +25,30 @@ nano .env
 
 ### Set environment variables to enable a proposer
 
-<Callout type="warning">
+<Callout type="error">
   Do **not** use a private key that is valuable to you. The private key will be
   stored in plain text in the `.env` file, and this is not secure. There is a
   real risk of losing your assets. You should **only use a test account**.
+
+  To generate an isolated burner wallet locally:
+  ```bash
+  cast wallet new | tee /dev/tty | grep 'Private key:' | awk '{print "export PRIVATE_KEY="$3}' >> .env && source .env
+  ```
+  ```js
+  var ethers = require('ethers');  
+  var crypto = require('crypto');
+
+  var id = crypto.randomBytes(32).toString('hex');
+  var privateKey = "0x"+id;
+  console.log("SAVE BUT DO NOT SHARE THIS:", privateKey);
+
+  var wallet = new ethers.Wallet(privateKey);
+  console.log("Address: " + wallet.address);
+  ```
 </Callout>
 
+
+
 Set the following environment variables to enable your node as a proposer:
 
 - Set `ENABLE_PROPOSER` to `true`