ESM support

fixes #977

Author: btakita

esm/index.browser.mjs

@@ -0,0 +1,2 @@
+import '../papaparse.js';
+export default globalThis.Papa;

esm/index.mjs

@@ -0,0 +1,3 @@
+import { createRequire } from 'module';
+const require = createRequire(import.meta.url);
+export default require('../papaparse.js');

esm/package.json

@@ -0,0 +1,4 @@
+{
+	"module": "./index.mjs",
+	"browser": "./index.browser.mjs"
+}

package.json

@@ -35,6 +35,7 @@
 	},
 	"license": "MIT",
 	"main": "papaparse.js",
+	"module": "papaparse.mjs",
 	"browser": "papaparse.min.js",
 	"devDependencies": {
 		"chai": "^4.2.0",

papaparse.mjs

@@ -0,0 +1,2 @@
+import Papa from './esm';
+export default Papa;