message: add lerna and yarn install step
diff: @@ -24,9 +24,10 @@ To migrate your app from blockstack.js to stacks.js follow the steps in the [mig
  To setup the development environment for this repository, follow these steps:
  1. Clone this package.
  -2. Run `lerna bootstrap` to install dependencies
  -3. Run `lerna run build` to build packages
  -4. Run `lerna run test` to run tests
  +2. Make sure you have both `lerna` and `yarn` installed globally
  +3. Run `lerna bootstrap` to install dependencies
  +4. Run `lerna run build` to build packages
  +5. Run `lerna run test` to run tests
  ## Documentation
  