chore: fix npm to yarn in contributing.md and package.json (#3274)

* chore: fix npm to yarn in contributing.md

* chore: fix npm pack to yarn pack

CONTRIBUTING.md

@@ -5,7 +5,7 @@
 ### Option 1 - Manual
 
 1. Fork and clone the repo
-1. Run `npm install` to install dependencies
+1. Run `yarn` to install dependencies
 1. Create a branch for your PR with `git checkout -b your-branch-name`
 
 > To keep `master` branch pointing to remote repository and make pull requests from branches on your fork. To do this, run:

src/packages/utils/package.json

@@ -57,6 +57,6 @@
   "scripts": {
     "build:umd": "cross-env NODE_ENV=production webpack --config webpack.prod.config.js",
     "build:umd:withAnalyzer": "cross-env NODE_ENV=production ANALYZER=true webpack --config webpack.prod.config.js",
-    "pack": "yarn build:umd && npm pack"
+    "pack": "yarn build:umd && yarn pack"
   }
 }