Recommend npm instead (#30)

Author: alanorozco

README.md

@@ -13,7 +13,7 @@ hosted `v0.js`).
 First, add the `@ampproject/storybook-addon` to your project:
 
 ```sh
-yarn add @ampproject/storybook-addon --dev
+npm install --save-dev @ampproject/storybook-addon
 ```
 
 Second, register the `@ampproject/storybook-addon` to your

package.json

@@ -44,12 +44,12 @@
   },
   "scripts": {
     "dev": "tsc --watch --preserveWatchOutput",
-    "build": "yarn build:esm && yarn build:cjs",
+    "build": "npm run build:esm && npm run build:cjs",
     "build:esm": "tsc",
     "build:cjs": "tsc --module commonjs --outDir cjs",
     "test": "echo 'No tests' && exit 0",
     "clean": "rm -r esm cjs",
-    "prepublishOnly": "yarn build",
+    "prepublishOnly": "npm run build",
     "storybook": "start-storybook -p 9009 -s public -c test/.storybook",
     "build-storybook": "build-storybook -s public -c test/.storybook"
   },