Merge 141a300 into 9ceaaa7

.eslintignore

@@ -4,3 +4,4 @@ dist/
 node_modules
 support/demo_template/sample.js
 benchmark/extra/
+rollup.config.js

.gitignore

@@ -4,3 +4,4 @@ coverage/
 demo/
 apidoc/
 *.log
+*.mjs

package.json

@@ -12,14 +12,19 @@
   "repository": "markdown-it/markdown-it",
   "license": "MIT",
   "main": "index.js",
+  "module": "index.mjs",
   "bin": {
     "markdown-it": "bin/markdown-it.js"
   },
   "scripts": {
-    "test": "make test"
+    "build": "rollup -c",
+    "prepare": "npm run build",
+    "test": "make test",
+    "watch": "rollup -c -w"
   },
   "files": [
     "index.js",
+    "index.mjs",
     "bin/",
     "lib/",
     "dist/"
@@ -56,6 +61,10 @@
     "mocha": "^6.1.4",
     "ndoc": "^5.0.0",
     "pug-cli": "^1.0.0-alpha6",
+    "rollup": "^1.26.3",
+    "rollup-plugin-commonjs": "^10.1.0",
+    "rollup-plugin-json": "^4.0.0",
+    "rollup-plugin-node-resolve": "^5.2.0",
     "stylus": "^0.54.5",
     "supertest": "^4.0.2",
     "terser": "^4.1.2"

rollup.config.js

@@ -0,0 +1,18 @@
+import commonjs from 'rollup-plugin-commonjs';
+import nodeResolve from 'rollup-plugin-node-resolve';
+import json from 'rollup-plugin-json';
+
+export default {
+  input: 'index.js',
+  output: {
+    file: 'index.mjs',
+    format: 'esm'
+  },
+  plugins: [
+    json(),
+    nodeResolve({
+      preferBuiltins: false
+    }),
+    commonjs()
+  ]
+};