Closes Mosuswalks#2: Get CVV not CV_CODE from .env file

As described in Mosuswalks#2, the README tells the user to create a `.env` file
with a `CVC` variable in it but the `bot.js` file references a `CV_CODE`
variable in the dotenv file which doesn't exists. It's actually called a
Card Verification Value (CVV) code and not a CVC code and hence the
variable names were adjusted to match that.

README.md

@@ -123,7 +123,7 @@ npm install
 ```sh
 [email protected]
 PASS=yournikeaccountpassword
-CVC=yourcreditcardcvc
+CVV=yourcreditcardcvv
 ```
 
 2. In the bot.js file, edit the following lines.

bot.js

@@ -28,8 +28,8 @@ const runSnkrBot = () => {
 	const email = process.env.EMAIL;
 	const pass = process.env.PASS;
 
-	// cv_code: 3-digit credit card validation code for the card saved to your Nike.com account
-	const cv_code = process.env.CV_CODE
+	// cvv_code: 3-digit credit card validation value for the card saved to your Nike.com account
+	const cvv_code = process.env.CVV
 
 	// size: the shoe size, as you see in the table of sizes on a product page, e.g., 'M 9 / W 10.5'
 	const size = 'US M 9.5 / W 11';
@@ -273,7 +273,7 @@ const runSnkrBot = () => {
 			() => (document.getElementById("cvNumber").focus())
 		);	
 		await target_frame.waitFor(1000);
-		await page.keyboard.type(cv_code, {delay: 10});
+		await page.keyboard.type(cvv_code, {delay: 10});
 
 
 		//#### LOG / DEBUG