Added 8 to make example more clear

[Mark-777-0]

Some exchanges have 8 to start their wallets: Binance, Bitfinex, KuCoinhave wallet adresses starting with digit '8'.

And the monero donate address starts with an 8, so saying they start with 4 might be confusing as alphatomcat said.

Closes #1947

[Mark-777-0]

closes #1947

[netlify[bot]]

✅ Deploy Preview for barolo-time-757cf9 ready!

Built without sensitive environment variables

Name	Link
🔨 Latest commit	3790c8c22ea910a50c52fa19c63f3a243383dae6
🔍 Latest deploy log	https://app.netlify.com/sites/barolo-time-757cf9/deploys/62bca553e9acc6000831da8a
😎 Deploy Preview	https://deploy-preview-1990--barolo-time-757cf9.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

---

To edit notification comments on pull requests, go to your Netlify site settings.

[selsta]

@Mark-777-0 add Closes https://github.com/monero-project/monero-site/issues/1947 in your first comment so that it automatically closes, it doesn't work when you write it in the second comment.

[Mark-777-0]

@Mark-777-0 add Closes #1947 in your first comment so that it automatically closes, it doesn't work when you write it in the second comment.

I added it, but not sure if it worked.