docs: fix docs for Installation multiple compilers

[kevupton]

// hardhat.config.js

... // your plugin imports and whatnot go here

module.exports = {
  ... // your other hardhat settings go here
  solidity: {
    ... // your other Solidity settings go here
    settings: {
      outputSelection: {
        "*": {
          "*": ["storageLayout"]
        }
      }
    }
  }
}

With also:

// hardhat.config.js

... // your plugin imports and whatnot go here

module.exports = {
  ... // your other hardhat settings go here
  solidity: {
    ... // your other Solidity settings go here
    compilers: [
      {
        ...// compiler options
        settings: {
          outputSelection: {
            "*": {
              "*": ["storageLayout"]
            }
          }
      }
    }
  }
}

[wei3erHase]

hi @kevupton, please submit a PR with the proposed changes!