Minimalist Markdown Editor

manifest.json

{
  "update_url": "https://clients2.google.com/service/update2/crx",
  "name": "Minimalist Markdown Editor",
  "description": "This is the simplest and slickest Markdown editor. Just write Markdown and see what it looks like as you type.",
  "version": "3.4.1",
  "app": {
    "background": {
      "scripts": [
        "js/background.js"
      ]
    }
  },
  "manifest_version": 2,
  "icons": {
    "16": "assets/icon-16.png",
    "48": "assets/icon-48.png",
    "128": "assets/icon-128.png"
  },
  "permissions": [
    "storage",
    "unlimitedStorage",
    {
      "fileSystem": [
        "write",
        "retainEntries"
      ]
    }
  ],
  "offline_enabled": true,
  "sandbox": {
    "pages": [
      "sandbox/preview.html"
    ]
  }
}