Use ESM

Author: wooorm

.gitignore

@@ -1,8 +1,5 @@
 .DS_Store
 *.log
-.nyc_output/
 coverage/
 node_modules/
-unist-util-source.js
-unist-util-source.min.js
 yarn.lock

.npmc renamed to .npmrc

@@ -1,5 +1,2 @@
 coverage/
-unist-util-source.js
-unist-util-source.min.js
-*.json
 *.md

.prettierignore

@@ -1,12 +1,8 @@
-'use strict'
-
-var location = require('vfile-location')
-
-module.exports = source
+import location from 'vfile-location'
 
 var search = /\r?\n|\r/g
 
-function source(value, file) {
+export function source(value, file) {
   var doc = String(file)
   var loc = location(file)
   var position = (value && value.position) || value || {}