chore: update flag comments in scripts

[leovct]

Ensure that the value specified in the flags for network is utilised.

# before
$ npm run truffle exec scripts/deposit.js -- network bor 0xe249c8135a138fF48C8b79Ef7ABe8c0C902cC29
> matic-protocol@0.3.2 truffle
> truffle

Using network 'development'.
...

# after
$ npm run truffle exec scripts/deposit.js -- --network bor 0xe249c8135a138fF48C8b79Ef7ABe8c0C902cC29

> matic-protocol@0.3.2 truffle
> truffle

Using network 'bor'.