docs(btc_staking_tools): add Coinone to supported exchanges list (#424)

Author: kkkk666

docs/stakers/btc_stakers/btc_staking_tools.mdx

@@ -91,6 +91,7 @@ A list of crypto exchanges that will support BTC Staking.
 | CoinEX | ✅ |
 | Kucoin | ❌ |
 | BingX | ❌ |
+| Coinone | ✅ |
 
 ## Liquid Staking Token Projects