Add eslint/prettier config.

Author: ryanwelcher

.eslintrc

@@ -0,0 +1,3 @@
+{
+	"extends": [ "plugin:@wordpress/eslint-plugin/recommended" ]
+}

package.json

@@ -5,11 +5,18 @@
 	"main": "index.js",
 	"scripts": {
 		"start": "wp-scripts start",
-		"build": "wp-scripts build"
+		"build": "wp-scripts build",
+		"plugin-zip": "wp-scripts plugin-zip",
+		"format": "wp-scripts format"
 	},
+	"files": [
+		"build",
+		"index.php"
+	],
+	"prettier": "@wordpress/prettier-config",
 	"keywords": [],
 	"author": "",
-	"license": "GPL v2 or later",
+	"license": "GPLv2 or later",
 	"devDependencies": {
 		"@wordpress/scripts": "^24.6.0"
 	}