chore: update README.md example to use ESM

.prettierignore

@@ -1,3 +1,4 @@
 test/fixtures/**
 .nyc_output/**
-package-lock.json
+package-lock.json
+lib

README.md

@@ -31,8 +31,10 @@ yarn add @metalsmith/metadata
 Pass the options to `Metalsmith#use`. The options object is in the format `{ 'metadata.key': 'path/to/(file.ext|dir)' }`. Relative file/directory paths are resolved to `metalsmith.directory()`. Directory option keys will include direct children of the directory, see [Mapping nested metadata directories](#mapping-nested-metadata-directories) for creating nested directory structures.
 
 ```js
-const Metalsmith = require('metalsmith')
-const metadata = require('@metalsmith/metadata')
+import Metalsmith from 'metalsmith'
+import metadata from '@metalsmith/metadata'
+
+const __dirname = dirname(new URL(import.meta.url).pathname)
 
 Metalsmith(__dirname)
   .use(

package.json

@@ -43,7 +43,7 @@
     "lint": "eslint --cache --fix \"{src,test}/**/*.js\"",
     "lint:check": "eslint --cache --fix-dry-run  \"{src,test}/**/*.js\"",
     "release": "release-it .",
-    "build": "microbundle --target node --no-sourcemap -f cjs,esm --strict",
+    "build": "microbundle --target node --no-sourcemap -f cjs,esm --strict --generateTypes=false",
     "pretest": "npm run build",
     "test": "nyc mocha -t 5000"
   },