Init markdown lib only when it's needed when posting a note to blog

browser/main/NoteList/index.js

@@ -21,7 +21,6 @@ import Markdown from '../../lib/markdown'
 const { remote } = require('electron')
 const { Menu, MenuItem, dialog } = remote
 const WP_POST_PATH = '/wp/v2/posts'
-const markdown = new Markdown()
 
 function sortByCreatedAt (a, b) {
   return new Date(b.createdAt) - new Date(a.createdAt)
@@ -710,6 +709,7 @@ class NoteList extends React.Component {
       authToken = `Bearer ${token}`
     }
     const contentToRender = firstNote.content.replace(`# ${firstNote.title}`, '')
+    const markdown = new Markdown()
     const data = {
       title: firstNote.title,
       content: markdown.render(contentToRender),