Turn export into an object

we have no options

src/index.js

@@ -1,4 +1,4 @@
-export default (options = {}) => ({
+export default {
   extensions: [
     {
       name: 'mfm',
@@ -37,4 +37,4 @@ export default (options = {}) => ({
       },
     },
   ]
-})
+}

test/index.test.js

@@ -2,17 +2,13 @@ import { marked } from 'marked'
 import markedMfm from '../src/index.js'
 
 describe('marked-mfm', () => {
-  beforeEach(() => {
-    marked.setOptions(marked.getDefaults())
-  })
-
   test('inline', () => {
-    marked.use(markedMfm())
+    marked.use(markedMfm)
     expect(marked('$[x2 this text is bigger]')).toBe('<p><span style="display: inline-block" class="x2">this text is bigger</span></p>\n')
   })
 
   test('nested', () => {
-    marked.use(markedMfm())
+    marked.use(markedMfm)
     expect(marked('$[twitch twitch $[sparkle sparkle]]')).toBe('<p><span style="display: inline-block" class="twitch">twitch <span style="display: inline-block" class="sparkle">sparkle</span></span></p>\n')
   })
 })