Add the ability to launch a testnet with the deploy script

[0x3639]

Instructions from another project for setting up a devnet. Review and integrate.

https://github.com/KingGorrin/znn_ptlc_use_cases_go/blob/main/docs/setup-devnet-linux-x64.md

[coinselor]

In #19, I proposed we use: --deploy testnet.