Add empty lines in solidity snippet

Author: fvictorio

docs/src/content/ignition/docs/advanced/migrating.md

@@ -97,13 +97,16 @@ contract Token {
     uint256 public totalSupply = 1000000;
     address public owner;
     mapping(address => uint256) balances;
+
     constructor(address _owner) {
         balances[_owner] = totalSupply;
         owner = _owner;
     }
+
     function balanceOf(address account) external view returns (uint256) {
         return balances[account];
     }
+
     function transfer(address to, uint256 amount) external {
         require(balances[msg.sender] >= amount, "Not enough tokens");
         balances[msg.sender] -= amount;