Correction of "Command-line interface" document.

[june-in-exile]

As I read the guide in "Command-line interface" document, I found that there isn’t a maci/contracts path in this project. The correct path should be maci/packages/cli.

Additionally, I tried running pnpm run hardhat in maci/packages/cli, but it failed (as shown in the screenshot). I guess the proper instruction here is npx hardhat node?