Add es modules entry point

Author: lewisl9029

.babelrc-esm

@@ -0,0 +1,18 @@
+{
+  "presets": [
+    [
+      "@babel/preset-env",
+      {
+        "modules": false,
+        "targets": {
+          "esmodules": true
+        }
+      }
+    ],
+    "@babel/preset-react"
+  ],
+  "plugins": [
+    "@babel/plugin-proposal-object-rest-spread",
+    "@babel/plugin-proposal-class-properties"
+  ]
+}

.gitignore

@@ -1,5 +1,6 @@
 node_modules
 coverage
 lib
+esm
 npm-debug.log.*
 .DS_Store

package.json

@@ -3,18 +3,20 @@
   "version": "0.7.1",
   "description": "Intro.js React Wrapper",
   "main": "lib/index.js",
+  "module": "esm/index.js",
   "types": "index.d.ts",
   "scripts": {
-    "prebuild": "rimraf lib/*",
+    "prebuild": "rimraf lib/* && rimraf esm/*",
     "build": "babel --ignore '**/*.test.js' --out-dir lib src",
+    "build:esm": "babel --ignore '**/*.test.js' --out-dir esm --config-file ./.babelrc-esm --no-babelrc src",
     "build:watch": "npm run build -- --watch",
     "lint": "eslint src",
     "test": "jest",
     "test:watch": "jest --watch",
     "test:coverage": "jest --coverage && open coverage/index.html",
     "test:ci": "jest --coverage",
     "precommit": "lint-staged",
-    "prepublish": "npm run build"
+    "prepublish": "npm run build && npm run build:esm"
   },
   "devDependencies": {
     "@babel/cli": "7.8.4",
@@ -80,6 +82,7 @@
   },
   "files": [
     "lib",
+    "esm",
     "src",
     "index.d.ts"
   ]