Update docs/pos/how-to/operate-validator-node/validator-best-practices.md

Co-authored-by: Dra Murphy <149679879+kmurphypolygon@users.noreply.github.com>

Author: hsutaiyu

docs/pos/how-to/operate-validator-node/validator-best-practices.md

@@ -10,8 +10,8 @@ The *signer wallet* is an address that is used for signing Heimdall blocks, chec
 
 The validator must keep two types of balances in this wallet:
 
-- MATIC tokens on Heimdall (through top-up transactions) to perform validator responsibilities on Heimdall
-- ETH on Ethereum chain to send checkpoints on Ethereum
+- MATIC tokens on Heimdall (through top-up transactions) to perform validator responsibilities on Heimdall.
+- ETH on Ethereum to send checkpoints on Ethereum.
 
 The *owner wallet* is an address that is used for staking, re-staking, changing the signer key, withdrawing rewards, and managing delegation related parameters on the Ethereum chain.