Update .gitignore + add gatsby & gatsby-link + hello world page

.gitignore

@@ -57,3 +57,5 @@ typings/
 # dotenv environment variables file
 .env
 
+.cache/
+public

package.json

@@ -0,0 +1,14 @@
+{
+  "name": "gatsby-starter-hello-world",
+  "description": "Gatsby hello world starter",
+  "license": "MIT",
+  "scripts": {
+    "develop": "gatsby develop",
+    "build": "gatsby build",
+    "serve": "gatsby serve"
+  },
+  "dependencies": {
+    "gatsby": "^1.4.1",
+    "gatsby-link": "^1.4.1"
+  }
+}

src/pages/index.js

@@ -0,0 +1,3 @@
+import React from "react"
+
+export default () => <div>Hello world!</div>